Use of Natural Zeolite in Sustainable Agriculture

3rd Iran International Zeolite Conference (IIZC 2012)

Effect of Sodium MontmorilloniteNanoclay on the Water Absorbency of Carrageenan-Based NanocompositeSuperabsorbents

Gholam Reza Mahdavinia*, KarimJalili Department of Chemistry, Faculty of Science, University of Maragheh, P.O. Box 55181-83111,

Maragheh, Iran Corresponding Author: [email protected], Tel:0421-2273068, Fax:0421-2276060

1.Introduction Superabsorbents are type of three-dimensional hydrophilic polymers capable to swell and absorb a large amount of water. They are mainly used in sanitary goods for absorbing the body fluids and in soil conditioning and improving the water retention capability of soil in agriculture and horticulture. They are also found to be valuable in some specialized applications, including controlled delivery of bioactive agents and wastewater treatment. But, these superabsorbents mainly do not possess enough strength. Introducing of nano-clays into hydrogels compositions can be considered as one of the methods to improve this property of superabsorbents. Because of eco-friendly property of carrageenan, we attempted to synthesize of nanocompositesuperabsorbentsby introducing of this biopolymer. The present work describes the synthesis of crosslinked poly (sodium acrylate-co-acrylamide) in the presence of carrageenan biopolymer and sodium montmorillonitenanoclay.

Scheme 1 Structure of carrageenan

2.Experimental In general, clay was dispersed in 30 mL of distilled water and sired under magnetic stirrer for 24 h. Dispersed clay solution was transferred in a one-liter reactor equipped with mechanical stirrer. To control the reaction temperature, the reactor was placed in a water bath preset at 60 oC. Then, carrageenan was added to the solution containing clay and stirred for 2 h until completion of dissolution. AA was neutralized using appropriate NaOH 5 wt% at 0 oC, and AAm and MBA were dissolved in neutralized acrylic acid and were simultaneouslyadded into polymerization solution and allowed to stir for 1 h. Finally, KPS (0.1 g in 2 mL of water) as initiator was added into solution and stirred until superabsorbents formation. After this time, the nanocomposites were dried at ambient temperature for 1 week the dried samples were milled and sieved to 40-60 mesh sizes and kept away from light and moisture. To measure the water absorbency (WA) capacity of nanocomposites they were immersed in water and the absorbed water was calculated according to WA=(Ws-Wd)/Wd, where Ws and Wd are the weights of the samples swollen in water and in dry state, respectively. 3.Results and Discussions The type of dispersion of nanoclay in the superabsorbents matrix was studied using XRD technique. At first, we attempt to investigate the XRD patterns of nanocomposites by varying the clay content and the results are shown in Figure 1. The XRD profile of pristine Na-MMt(Fig 1a) shows a strong diffraction peak at 2θ = 7.6 corresponding to the distance of clay sheets with d spacing 11.61 A .˚ By changing the clay content up to 10wt%, no distinct diffraction peak was appeared in the XRD patterns and it can be concluded that the clay layers are completely exfoliated. But, when the clay content was reached to 18wt%, a diffractive peak was observed at 2θ = 4.3 and revealed that the nanoclay dispersion is in intercalated type. At high content of the clay, the negative charges on the surface of Na-MMt prevent the dispersion of clay as completely


disk-link nanoparticles and subsequently the monomers will diffuse between layers. The SEM micrograph of nanocomposite was shown in Figure 2 and showed a coarse and porous structure.

Figure 1 XRD profiles of (a) pristine clay (b) clay5 (c) clay10 and (d) clay18 (the suffix shows %wt of

clay)

Figure 2 SEM of nanocomposite

To investigate the influence of MMt on the swelling capacity, the polymerization was carried out at five different clay contents, ranging from 0 to 18 wt% of MMt and the results are shown in Figure3. The results revealed that swelling capacity increased by increasing the clay content up to 10 wt% of MMt. At 12 wt% of clay, maximum water uptake was obtained (117.8 g g-1). The corresponding increase in swellingup to 10 wt% of MMt could be attributed to increase in ionic osmotic pressure of nanocomposites. This osmotic pressure is due to the mobile ions on the nanoclay particles. By further increase in MMt content, the viscosity of polymerization medium will be increased and restricted the macroradicals movement; thereby decreasing the gel content and subsequent water absorbency content will be deceased.

Figure 2 Effect of clay content on the water absorbency of nanocomposites.

References

1. H.Eshel, L.Dahan, A.Dotan, H.DodiukS.KenigPolym Bull 61(2008)257 2. P.Liu, L.Zhang Sep PurifTechnol 58 (2007) 32 3. Y.Liu, W.Wang, Y.Jin, A.Wang Sep PurifTechnol 46(2011) 858

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WA

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)


The effect of natural zeolite on nutrient digestibility and milk production of dairy cow

F. Fatehi, A. Ghahremani, E. Froutan, M. Savari Faculty of Agricultural and Natural Resource, Department of Animal Science, University of Tehran, Karaj,

Iran. +989143805625, [email protected] 1.Introduction Over the last decades, the use of both natural and synthetic zeolites in animal nutrition has increased mainly to improve their performance (Pearson et al., 2008; Jonathan et al., 2008), improve production rates and rumen microbial activity, decrease mortality rate (Forouzani et al., 2004; Sadeghi and Shawrang, 2006) and improve digestibility (Forouzani et al. 2004). Zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations which have infinite, three dimensional structures (Shariatmadari, 2008; Durali and Tulay, 2011). These hydrated aluminosilicates of alkali and alkaline earth cations have unique properties such as the ability to lose and gain water reversibly to absorb molecules of appropriate diameter (absorption property) or acting as molecular sieves and to exchange their constituent cations without major change of their structure (Lithourgidis et al., 2011) The ion-exchange properties of zeolite could affect microbial and animal metabolism through the selective trapping and releasing of cations.These properties make zeolites useful in animal nutrition. 2.Result and discussion Sweeney (1980) demonstrated improving nitrogen, organic matter, and acid-detergent fibre digestibility when clinoptilolites were added to a high solubility protein diet of growing steers and heifers.Collum and Galyean (1983) reported that the total tract dry matter digestibility (DMD) was higher (P<.05) for the 1.25% clinoptilolitediet than for 2.5 or 5.0% clinoptilolite diets.Forouzani et al. (2004) reported that the total tract DM and CP Digestibilities were higher (P < 0·05) in zeolite diets compared with the control but the differences between 30 and 60-g/kg zeolite diets were not significant. Total tract NDF digestibility for diets with 30 and 60 g/kg zeolite was higher than the control diet significantly(table 1).The researchers explained that the positive effects of zeolite on NDF digestibility may be due to effect of zeolite on the pH of rumen contents and an increasing population and activity of cellulolytic bacteria.High-concentrate diets are often associated with lower ruminal pH and decreased fiber digestibility In addition, supplementing zeolite in dairy diets may improve nitrogen (N) utilization, because zeolite gradually releases excess ammonia (NH3) in the rumen and allows rumen microorganisms to capture the NH3 into microbial protein for assimilation into the animals’ digestive systems (Mumpton, 1999). The variations in milk characteristics and milk yield within a species depends on many factors such asgenetics, stage of lactation, daily variation, parity, type of diet, age, udder health and season (Haenlein, 2003). In particular, feeding system and environmental conditions have the major effect on milk characteristics. Ruiz et al. (2008) reported that zeolite addition is known and practiced in animal nutrition and the inclusion of these aluminosilicates is due to their physicochemical properties that permit better nutritional efficiency in ruminants.Katsoulos et al. (2006) and Bosi et al. (2002) observed no differences in milk yield of dairy cows supplemented with zeolite at 1 and 1.25% (based on dry matter). However, dairy cows fed 2.5% (Katsoulos et al., 2006) had higher milk production. Katsoulos et al. (2006) speculated that the higher milk production by cows fed 2.5% zeolite could be due to increasing production of propionate in the rumen or increasingpostruminal digestion of starch.McCollum and Galyean (1983) observed that when steers were fed on high concentrate diets, the molar proportions of propionate were increased by the addition of 2·5 %clinoptilolite in their ration but not by 1·25 %. Garcia Lopez and others (1992) reported that zeolites alter the postruminal pH, which becomes more acceptable for the action of alpha-amylase pancreatic enzyme in the digestion of compounds containing starch. A higher faecal pH, which indicates more complete digestion of dietary starch (Hemken and others 1984), and reduced faecal losses of grain have been observed when clinoptilolite was added to the ration of dairy cattle (Hemken and others 1984, Pond and Lee 1984, Garcia Lopez and others 1992), steers (Galyean and Chabot 1981) and growing lambs (Pond and others 1984). Hornig et al. (1999) observed a significant increase in milk fat, protein, and lactose for cows fedby diets containing 2% of clinoptilolitewhile Garcia Lopez et al., (1988) found only an improvement in milk fat, with


the same dietary addition.Bosi et al. (2002) reported that the zeolite supplementation did not affect milk fat. Dschaak et al. (2010) also reported that milk fat concentration did not differ among treatments with zeolite.Kamoun et al. (2011) reported that feeding different levels of zeolite (100 and 200 g/d) had no effect on milk fat and total solids, whereas Milk protein, lactose and not fat solid were significantly higherfor cows fed zeolite at the rate of 200 g compared to 100 g and control diet (Table2).Rousselet al. (1992) reported that adding of Zeolite to corn silage based diet increased milk fat percent at the 1.0% level and milk protein at the 1.5% level. Table1. Digestibility coefficients of dry matter (DM), crude protein (CP), neutral-detergent fibre(NDF) andacid-detergent fibre (ADF) of experimental diets

Parameters Control 30 g zeolite 60 g zeolite

DM 0·64b 0·73a 0·75a

CP 0·66b 0·74a 0·79a

NDF 0·74b 0·78a 0·78ab

ADF 0·65a 0·64a 0·59a

Table 2. Overall milk composition of experimental diets Parameters Control 100 g zeolite 200 g zeolite

Fat g/kg 41.03 ± 0.66 42.56 ± 0.52 43.03 ± 2.05

Protein g/kg 32.19 ± 0.40b 33.17 ±0.33b 34.85 ± 0.44a

Lactose g/kg 45.56 ± 0.42b 43.76 ±0.45b 46.59 ± 0.49a

Not Fat Solids g/kg 86.43 ± 0.66b 86.45 ± 1.12b 88.84 ± 1.41a

Total solids g/kg 130.43 ± 1.29 129.68 ± 1.36 131.93 ± 3.56


An Efficient One-Pot Synthesis of Polyhydroquinolines Using NaY-Zeolite

Mohammad Ali Bodaghi Fard,a,* Mahdia Hamidinasab,a Akbar Mobinikhaledi,a Kaveh Khosravi a

a Department of Chemistry, Faculty of Sciences, Arak University, Arak, 38156-88138, Iran. *Corresponding author. 0861-4173415, 0861-4173406, [email protected]

1.Introduction 1,4-dihydropyridine (1,4-DHP) and its derivatives represent the most promising group of compounds having broad range of biological activities such as vasodilator, bronchodilator, anti-atheroscerotic, anti-tumor, hepatoprotective agents.1 Owing to the wide spectrum of biological and medicinal activities, the synthesis of compounds having 1,4-dihydropyridine moeity has become an important target in recent years. 1,4-Dihydropyridines were synthesized more than a century ago by Hantzsch. Different other approaches for the syntheses of polyhydroquinoline derivatives have subsequently been reported.2 Each of the above methods has its own merits, while some of the methods are plagued by limitations of poor yields, longer reaction time, difficult work-up procedure, effluent pollution and use of expensive catalysts that are harmful to the environment. Green chemistry approaches are significant due to the reduction in byproducts, a reduction in waste produced and lowering of energy costs. The possibility of performing multi-component reactions with a natural heterogeneous catalyst could enhance their efficiency from an economic as well as ecological point of view. In continuation of our work on the applications of heterogeneous catalysts on organic transformations we report here a convenient and efficient method for the synthesis of polyhydroquinolines using NaY-zeolite as a catalyst (Scheme 1).

R-CHO

O

O

O O

OEt

NH4OAc+ + +NaY-zeoliteEtOH, reflux

NH

RO

OEt

O

1 2 3 4 5

Scheme 1

2.Experimental All of the products are known compounds and were identified by their physical and spectroscopic data (IR, NMR spectra and CHN analysis) with those reported in literature. The progress of reactions was monitored by TLC using n-hexane/EtOAc (2:1 v/v) as eluent.

General procedure for the synthesis of polyhydroquinoline: A mixture of aldehydes (2 mmol), dimedone (2 mmol), ethylacetoacetate (2 mmol), ammonium acetate (3 mmol) and NaY-Zeolite catalyst (100 mg) was refluxed in ethanol (15 mL) for appropriate times. The reaction was monitored by TLC. After completion of reaction, the reaction mixture filtered in hot condition to separate the catalyst, poured into crushed ice and the solid product, which separated was filtered and recrystallized from ethanol to get pure crystalline polyhydroquinoline derivatives.


3.Results and Discussion A series of polyhydroquinoline derivatives were prepared following the above method using various aldehydes (Scheme 1). Both aromatic and aliphatic aldehydes underwent the conversion smoothly. Aromatic aldehydes containing electron donating as well as electron withdrawing groups produce the appropriate products in good yields. The polyhydroquinoline derivatives were formed within 1—2 h in excellent yields (85—95%). In absence of the catalyst only poor yield of product could be detected within 3 h at the present experimental conditions. The present catalyst can conveniently be handled and removed from the reaction mixture. Moreover, it can be recovered and reused for at least three times without loss of its activity. In conclusion, we have developed a convenient and efficient protocol for one-pot synthesis of polyhydroquinolines by four-component coupling reactions of aldehydes, ethyl acetoacetate, dimedone and ammonium acetate in the presence of NaY-zeolite as a catalyst. The method is associated with several advantages such as simple experimental procedure, milder conditions, short reaction times, excellent yields and reusability of the catalyst.

References [1] R. Manmhold, B. Jablonka, W. Voight, K. Schoenafinger, E. Schraven; Eur. J. Med. Chem. 27 (1992) 229.

[2] a) W.-Y. Chen, J. Lu, J.-R. Jin, Lett. Org. Chem. 3 (2006) 317.; b) S. Ko, M. N. V. Sastry, C. Lin, C.-F. Yao Tetrahedron Lett. 46 (2005) 5771.; c) S. Ko, C.-F. Yao Tetrahedron 62 (2006) 7293.


Preparation and charachterization of nano NaX zeolite by conventional hydrothermal and

microwave heating methods

Mehdi Ansari, Abdolreza Aroujalian*, Ahmadreza Raisi, Mahdi Fathizadeh, Bahram Dabir

Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave., P.O.Box 15875-4413, Tehran, Iran

*Author for correspondence: Phone: (9821) 64543163, Fax: (9821) 66405847, E-mail: [email protected]

1.Introduction Zeolite X is a highly versatile molecular sieve from the faujasite family of zeolites whose 7.4 Å, three-dimensional pore structure and solid acidity make it useful as a catalyst, adsorbent, membrane, and others [1–3]. This type of zeolite is used for heavy metal adsorption [4], aromatics from aromatic/alkane mixtures [5] and para xylene [6] separation, as well as natural gas desulfurization [7] and as filler in polymeric membrane [8,9].

The synthesis of nanometer-dimension zeolites has received much attention in the past decade because nanometer-sized zeolitic crystals can have different properties than their micrometer-sized counterparts. The reduction of the particle size from the micrometer to the nanometer scale can change the mass and heattransfer resistances in catalytic and sorption processes, thereby improving the catalytic selectivity and reducing coke formation in some petroleum reactions. Furthermore, nanocrystalline zeolites can be used to fabricate zeolitic membranes and ordered porous materials [10].

In this paper, nano NaX zeolite was synthesized via conventional hydrothermal and microwave heating methods with agitation and temperature controlling.The prepared zeolite particles were characterized by X-ray powder diffraction (XRD) and Field-Emission Scanning Electron Microscope (FESEM) analysis.

2.Experimental The chemical reagents used included fumed silica (7nm, Sigma Alderich), NaOH (Merck, Darmstadt, Germany) and NaAlO2 (Sigma Alderich). The nanometer-sized faujasite-X zeolite was synthesized using both conventional and microwave heating.In both heating methods at first, aluminosilicate gel was prepared in a 250mL plastic bottle by mixing freshly prepared aluminate and silicate solutions together in the molar ratio 5.5 Na2O:1.0 Al2O3:4.0 SiO2:190 H2O. Typically, an aluminosilicate gel containing 5.34 g of NaOH, 2.42g of NaAlO2, 3.43 g of SiO2, and 50.0 g of H2O was adopted. The key step in the synthesis was the application of conventional or microwave heating. Heat drives the crystallization process. Conventional hydrothermal crystallization was conducted at 60 °C for 4 days in a shaker with a rotation rate of 250 rpm, while microwave heating proceed at 90 °C for 3 hours. The powdered products were recovered with centrifugation, washed with DI water until pH< 8, and then dried at room temperature for 24 h.

3.Results and Discussion

The XRD spectra of zeolites, provided in Figure 1, confirm that both zeolites are NaX with good crystallinity.The nanoNaXzeolite is very hydrophilic with entrance pores of approximately 7.4Å. The average crystal dimension was calculated by Scherrer’s equation from the diffraction peaks at 2Ө values of 6° [111], 16° [331], and 27° [642].

coskr

where k is the shape factor, λ is the x-ray wavelength, typically 1.54 Å, β is the line broadening at half the maximum intensity (FWHM) in radians, and θ is the Bragg angle. XRD patterns showed that the average crystal dimension for conventional zeolite and microwave heated zeolite were 105±9 and 74±6 nm, respectively.


(a) (b)

Figure 2 presents FESEM images of the NaXzeolite crystals. It can be seen that the FESEM images confirmed XRD results. The crystal size distribution of microwave-heated zeolites (Fig. 2a) was visually more uniform than conventionally heated zeolites (Fig. 2b).The microwave heating accelerates the crystallization reaction through dielectric heating effects. This method provides better heat transfer, faster reaction time, small and more uniforme crystalls when compared to other heating techniques.

Figure 1 – XRD powder patterns for (a) microwave and (b) conventionally heated

Figure 2 – FESEM images of nano NaX zeolite (a) microwave and (b) conventionally heated

References

[1] S. Sanga, Z. Liu, P. Tiana, Z. Liua, L. Qua, Y.Zhang, Materials Letters 60 (2006) 1131. [2] B. H. Wang, Y. Y. Xia, S. Y. Zhuang, Y. H. Zhang, Imaging Science Journal 25 (1998) 131. [3] S. Mintova, V. Valtchev, Stud Surf Sci Catal 125 (1999) 141. [4] Y. S. Oka, J. E. Yang, Y. S. Zhang, S. J. Kim, Journal of Hazardous Materials 147 (2007) 91. [5] M. Fathizadeh, M. Nikazar, JCEJ 42 (2009) 241. [6] C. R. Jacob, S. P. Varkey, P. Ratnasamy, Applied Catalysis A: General 182 (1999) 91. [7] S. Satokawa, Y. Kobayashi, H. Fujki, Sci tech catal 143 (2003) 399. [8] M. Fathizadeh, A. Aroujalian, A. Raisi, Journal of Membrane Science375 (2011), 88. [9] M. Fathizadeh, A. Aroujalian, A. Raisi, Desalination 284 (2012) 32. [10] B. Z. Zhan, M. A. White, M. Lumsden, J. M. Neuhaus, Chemistry of Materials 14 (2002) 3636.

(a) (b)


Hydrothermal Synthesis of Chabazite Zeolite

*Mohammadi .TKazemimoghadam, .M A. Bayat, Jafari, ., MNouri .A Research Centre for Membrane Separation Processes, Faculty of Chemical Engineering, Iran University of

Science and Technology (IUST), Narmak, Tehran, Iran Tel: +98 21 77240496, Fax: +98 21 77240495

*Corresponding author: E-mail address: [email protected] (T.Mohammadi)

1. Introduction

Chabazite (CHA) is a naturally occurring zeolite whose structure was first determined by Smith et al.. It consists of D6R units arranged in layers that are linked together by tilted 4-member rings. The pore structure comprises eight member rings 0.38 ×0.38 nm opening into large ellipsoidal cavities of 0.67 _ 1.0 nm[1]. Naturally occurring chabazite has been used successfully at some nuclear facilities to remove radioactive cesium-137 and strontium-90 from processing waters [2]. Zeolites with the CHA topology are of industrial interest, primarily as potential highly selective catalysts for application in the methanol to olefins (MTO) reaction.

2. Experimental

The chemical ingredients used in this study are sodium silicate solution, sodium hydroxide, sodium aluminum, potassium hydroxide and Di water.

2.1. Synthesis NaY zeolite

Zeolite NaY with a composition ratio of 4.62 Na2O:Al2O3: 10 SiO2:x H2O (molar ratio) was prepared using the method suggested by Ginter et al. [40]. Crystallization down at 100 C for 8 h then filtered and dried at 110 0C for 3 h.

2.2. Synthesis HY zeolite

Ion exchange was carried out at 368 K for 1 h using an 1N aqueous solution of NH4CL. After each ion exchange in the solution, The sample was then calcined in dry air. The temperature profile during the calcination was as follows: raising from 293 to 850 K with 3 K/min, maintaining 850 K for 1 h, and cooling to room temperature.

3.3. Synthesis Chabazite zeolite

Synthetic CHA zeolites were grown from a reaction mixture of batch composition: 5.2SiO2:1Al2O3:2K2O:224H2O. In a typical synthesis, the reaction suspension was prepared by dissolving a given amount of KOH pellets in water, followed by addition of the heat-treated HY zeolites to the above alkaline solution. The resulting mixture was stirred at room temperature for 10–20 min and then charged into a polytetrafluoroethylene (PTFE) container. The hydrothermal synthesis was conducted at 95 0C for 4 days.

3. Results and Discussion

Fig. 1 shows the XRD patterns of NaY zeolite. Amount of ion exchange on synthesis HY zeolite characterize by XRF analysis. XRF results before and after ion exchange gives in table 1. this result showed that ion exchange successfully done 99/9%. XRD patterns of Chabazite zeolite shows in Fig. 2. According to Figure 2 Pure of Chabazite zeolite was obtained. The SEM micrographs of Chabazite zeolite are displayed in Fig. 3.


table1. XRF results before and after ion exchange NaY zeolite

MnO TiO2 MgO K2O Na2O CaO Fe2O3 Al2O3 SiO2 Sample % % % % % % % % %

0.001 0.001 0.01 0.04 13.62 0.17 0.09 18.33 55.61 NaY 0.001 0.026 0.01 0.01 0.12 0.01 0.01 21.69 63.75 HY

Fig. 3: SEM micrographs of Chabazite zeolite

Reference [1] Xiansen Li, Hidetoshi Kita, ” Influence of the hydrothermal synthetic parameters on the pervaporative separation performances of CHA-type zeolite membranes”, Microporous and Mesoporous Materials 143 (2011) 270–276

[2] Firas N. Ridha, Paul A. Webley, “Investigation of the possibility of low pressure encapsulation of carbon dioxide in potassium chabazite (KCHA) and sodium chabazite (NaCHA) zeolites”, Journal of Colloid and Interface Science 337 (2009) 332–337.

0

500

1000

1500

2000

4 9 14 19 24 29 34 39 44 49

Inte

nsity

2 Teta

0

200

400

600

4 9 14 19 24 29 34 39 44 49

Inte

nsity

2 Teta

Fig. 1: XRD patterns of NaY zeolite Fig. 2: XRD patterns of Chabazite zeolite


Effects of Hydrothermal Parameters on Synthesis of Nano Crystal Zeolite NaY

*Mohammadi .TKazemimoghadam, .MA. Bayat, Jafari, ., MNouri .A Research Centre for Membrane Separation Processes, Faculty of Chemical Engineering, Iran University of

Science and Technology (IUST), Narmak, Tehran, Iran Tel: +98 21 77240496, Fax: +98 21 77240495


1. Introduction The FAU type zeolite has cavities with a diameter of 1.3 nm interconnected by pores of 0.74 nm; depending on its Si/Al ratio, and thus can be distinguished into X-type zeolite (Si/Al = 1.0–1.5) and Y-type zeolite (Si/Al > 1.5) [1]. The main applications of synthetic zeolite Y are in the fields of fluid catalytic cracking (FCC) of vacuum gasoil and adsorption of volatile organics from wet off-gas streams [2]. It has been found that the size of zeolite crystals could exert a significant impact on the catalytic performance [3]. The synthesis of zeolite Y with small crystal size has received much attention. In this research, the optimization of reaction conditions for the synthesis of nano-sized zeolite Y with narrow size distribution as studied in the absence of organic template within a short reaction time at the atmospheric pressure.

2.Experimental

Zeolite NaY with a composition ratio of 4.62 Na2O:Al2O3: 10 SiO2:x H2O (molar ratio) was prepared using the method suggested by Ginter et al. . The sodium silicate solution was prepared by mixing sodium silicate (Na2SiO3) with sodium hydroxide (NaOH) and DI water. The sodium aluminate solution was prepared by mixing sodium aluminum (Na2Al2O3), sodium hydroxide and Di water. The initial precursor was prepared by mixing the required amounts of sodium aluminate solution and sodium silicate solution together and stirred moderately for at least 10 min. The mixed solution which was called seed gel was left at ambient temperature for 24 h. The composition ratio of the seed gel was 10.67 Na2O:Al2O3:10 SiO2:x H2O. Feedstock gel (4.30 Na2O:Al2O3:10 SiO2:x H2O) was prepared. The overall gel was prepared by slowly adding seed gel to feedstock gel and stirring vigorously for up to 20 min. After the gel was transferred to the autoclave for crystallization at 100 C for 8 h then filtered and dried at 110 C for 3 h.


In zeolite crystallization, the role of water content has been known to be very important as a mineralizing agent. Fig. 1 shows the XRD patterns of samples produced using different H2O/SiO2 molar ratios under the same synthetic conditions. Three water contents of 18, 30 and 42 were studied. According to Figure 1 When the H2O/SiO2 molar ratio is increased, Crystalinity decreased. The primary crystal size of each NaY sample was estimated by Scherrer’s equation and SEM micrographs summarized in Table 1. The SEM micrographs of sample are displayed in Fig. 2. H2O/SiO2 samples (n = 18) are uniform in crystal size, and the individual aggregates are composed of closely packed nanocrystals, whose sizes vary from 25 to 120 nm. This important observation confirms that the zeolite gel with lower water content favors the formation of smaller FAU zeolite nanocrystals. should be note that if water content increases, crystalinity decrease.


Table4. Primary nanocrystal sizes and particle sizes of porous aggregated NaY zeolite particles.

No. Reaction Time(h)

Crystalization Temprature

(°C)

H2O/SiO2 Crystallite size from XRD (nm)

Particle size from SEM (nm)

Z1 8 100 18 23 25-150 Z2 8 100 30 19 - Z3 8 100 42 13 -

Figure 1: XRD patterns of samples taken out at (a) H2O/SiO2=18, (b) H2O/SiO2=18 and (c) H2O/SiO2=18 prepared under the same synthetic conditions (8h and 100°C ).

Fig. 2: SEM micrographs of sample (t=8h and T=100°C) for H2O/SiO2=18

Reference [1] C. Algieri, P. Bernardo, A novel seeding procedure for preparing tubular NaY zeolite membranes, J. Microporous and Mesoporous Materials. 119 (2009) 129–136.

[2] D. Karami, S. Rohani, Synthesis of pure zeolite Y using soluble silicate, a two-level factorial experimental design, J Chem. Eng. and Processing. 48 (2009) 1288–1292.

[3] S. Mintova, V. Valtchev, Synthesis of nanosized FAU-type zeolite, J. Stud. Surf. Sci. Catal. 125 (1999) 141-148.


Synthesis ofNaAnano zeolite without using organic template

*Toraj MohammadiMansoorKazemimoghadam, ,Amir Nouri, Mostafa Jafari Research Centre for Membrane Separation Processes, Faculty of Chemical Engineering, Iran University of Science

and Technology (IUST), Narmak, Tehran, Iran Tel: +98 21 77240496, Fax: +98 21 77240495


1.Introduaction Zeolites are crystalline materials that have a highly regular and open microporous structure [1]. The size of their pores openings ranges from 0.3 to 1 nm. Different framework compositions (Si/Al ratio) causes different ion-exchange properties, hydrophilic or hydrophobic characteristics of the materials, and acid sites with different strengths and densities[2]. Zeolite A (LTA type) is one of the synthetic zeolites with very small pores. Zeolite NaA has a pore diameter of 4 Å, which can be modified either to 5 Å or 3 Å by ion-exchange with aqueous solutions of calcium or potassium salts [3]. Zeolite A is normally synthesized in the Na+ form, Na12Al12Si12O48. 27H2O, and it has a three-dimensional pore structure. Reduction of their particle size of from micrometer to nanometer scale leads to substantial changes of zeolites properties [4]. Small crystals provide unique advantages of having relatively high external surface (area-to-volume) ratio and reduced mass transfer resistance. Also, much smaller crystals of zeolites act as better precursor materials for synthesis of continuous, highly oriented, and ultra thinfilms [5].As a result, in recent years, synthesis of nanocrystalline zeolites has received much attention [4]. In this paper synthesis of nano particles of zeolite NaA is presented.

2.Experimental Zeolite NaA was synthesized via hydrothermal method in a PTFE autoclave. Reagents were sodium aluminate (Sigma-Aldrich, 56% Al2O3) as a source of Al, sodium silicate (Merck, 25–28% SiO2) as a source of Si, sodium hydroxide (NaOH, Merck, 98%) and deionized water.Synthesis gel composition of zeolite NaA was 1.0Al2O3: 2.7 SiO2: 5.85 N2O: 180 H2O. Synthesis solution was prepared by mixing aluminate and silicate solutions. NaOH (4.47 g) was dissolved in 43.1 ml of distilled water. The solution was divided into two equal volumes and kept in polypropylene bottles. Aluminate solution was prepared by adding 2.91 g sodium aluminate to one part of the solution. It was mixed until cleared. Silicate solution was prepared by adding 9.182 g sodium silicate to another part of the NaOH solution. Silicate solution was then poured into aluminate solution and mixed until a thick homogenized gel was formed.Afterward,the gel was heated at temperatures ranging from 60 to80 °C for 6 h.The results are presented in Table 1. 3.Results and Discussion Temperature is an important factor in synthesis of zeolites. All the researches regarding the zeolites synthesis pay particular attention to the crystallization temperature due to its strong effect on formation of zeolites. The desired zeolite phase typically can only be obtained within a specific temperature range. Nucleation and crystal growth are strongly affected by the crystallization temperature. Increasingtemperature increases both the nucleation rate and the crystal growth rate, in particular, the crystal growth rate over the nucleation rate. Thus, larger crystals are obtained at higher temperatures due to the higher growth rates.The increasing temperature can also affect the type of synthesized zeolites and both NaA and NaX zeolites are formed with increasing temperature.Nano particles of NaA zeolite was synthesized using a gele composition of 1.0Al2O3: 2.7 SiO2: 5.85 N2O: 180. Increasing temperature caused formation of both NaA and NaX zeolites. Table 1) Characteristics of the synthesized zeolites

NO Reaction Time(h)

Reaction Temperature()

Zeolite phase

Crystallinity% Particle size(nm)

a 6 60 NaA 70 100-250


b 6 70 NaA 100 100-400 c 6 80 NaA+NaX 100 200-600

Figure 1) XRD patterns of the zeolites synthesized at (a)60 , (b)70 and (c)80

Figure. 2) SEM micrographs of the zeolites synthesized at (t=6h)at (a) 60, (b) 70 and (c) 80

References

[1] R. M. Barrer, Zeolites and Clay Minerals and Sorbents and Molecular Sieves, Academic Press, New York, 1978. [2] M. Smaihi, O.Barida, V. Valtchev, Investigation of the Crystallization Stages of LTA-Type Zeolite by Complementary Characterization Techniques,J. Inorg. Chem.( 2003) 4370-4377. [3] C. Kong, T. Tsuru, Zeolite nanocrystals prepared from zeolite micro particles by a Centrifugation-assisted grinding method.J.Chem.Eng. and Processing, 49 (2010)809–814. [4] T. Brar, P. France. G. Smirniotis, Control of Crystal Size and Distribution of Zeolite A,J. Ind. Eng. Chem. Res.40( 2001)1133-1139.


[5] Y. Tao, H. Kanoh, K. Kaneko, Synthesis of Mesoporous Zeolite A by Resorcinol-Formaldehyde Aerogel Templating, JLangmuir. 21(2005) 504-507.


Alumina support preparation for zeolite membranes

Mostafa Jafari, Amir Nouri, Korosh Shafiei, Mansoor Kazemimoghadam, Toraj Mohammadi*

Research Centre for Membrane Separation Processes, Faculty of Chemical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, Iran Tel: +98 21 77240496, Fax: +98 21 77240495

*Corresponding author: E-mail address: [email protected] (T.Mohammadi) 1. Introduction

An asymmetric zeolite membrane usually consists of a top layer with separation properties and a support layer. The support must have low resistance to the permeate flow and smooth surface because only then the thin top layer can be applied without introduction of defects. In order to obtain the maximum permeation flux through the composite zeolite membrane, the top layer has to be as thin as possible. For this reason,a membrane support with smooth surface is required. -alumina membrane support has received much attention due to its consistency with low silica zeolite membranes. Low cost and abundance of alumina as ceramic material makes it an ideal material for commercial manufacturing of inorganic membrane supports. Since alumina powder is available in highly purified grades and wide ranges of particle size, it is ideally suited for fundamental studies in material research [1]. However, it is difficult to have predictable quality by sintering method. Demands on the support are therefore high strength, narrow pore size distribution, high permeability and surface smoothness [2]. Sintering is a processing technique used to shape density-controlled materials and components from metal or/and ceramic powders by applying thermal energy [3]. This technique was used to produce suitable supports for zeolite membranes.

2.Experimental

In the experiments in this research, two industrial grades of α-alumina were supplied and polyvinyl alcohol(PVA) was used as binder.Specifications of the materials are presented in Table 1. An oil type pressing was used for molding of non-sintered alumina pellets. Concentration of the binder solution was 1.2wt% in distilled water.


The results of porosity and water permeability are presented in Table 2.

Table1)Specification of raw materials

Material name specification supplier −alumina powder(WDR4) alumina:99.6%

cut of diameter≈4 m Fibrona

−alumina powder(SRM30) alumina:99.6% cut of diameter≈1 m

Fibrona

PVA Molecular weight:60000 Merck


Table 2)Porosity and water permeability of the supports

Sample NO.

Alumina 1 micron %

Volume of binder in 30

gr powder(cm3)

Pressing pressure(bar

)

Sintering temp()

Porosity %

Water permeability (kg/m2.h.bar)

S1 0 1 300 1350 46.7 low mechanical resistance

S2 0 2 400 1425 46.7 2925.2 S3 0 3 500 1500 40.9 2467.6 S4 50 1 400 1500 35.7 231.1 S5 50 2 500 1350 45.9 336.2 S6 50 3 300 1425 41.4 614.3 S7 100 1 500 1425 41.6 155.7 S8 100 2 300 1500 33 208.8 S9 100 3 400 1350 47.8 180.5

Effect of parameters on porosity It was investigated that sintering temperature is the most effective parameter percenton porosity by taguchi analyzing of the response. After that, pressing pressure is more effective onepercent. Concentration of the binder and alumina powder size hasthe same level of importance percents.The results are shown in Figure1.

Figure 1)Effects of parameters on porosity of the supports

Effect of parameters on permeability

It was also investigated that powder size of alumina powder is the most effective parameter percenton permeability by taguchi analyzing of the response. After that, sintering temperature and binder concentration are more effective ones in the same order percent.The results are shown in Figure2.

Figure 2)Effects of parameters on permeability of the supports


SEM

SEM images of the surface and the cross section of the supports are presented in are presented in Figure 3. Higher water permeability of the support (S2) can be attributed to its more porous structure.

Figure 3)SEM photos of the supports

References

[1] H. Bissett, J. Zah, H.M. Krieg, Powder Technology 181 (2008) 57–66

[2] P. Maarten Biesheuvel, Henk Verweij, Journal of Membrane Science 156 (1999) 141-152.

[3] S.-J.L. Kang, Sintering: Densification, Grain Growth & Microstructure, Elsevier Butterworth-Heinemann, Burlington,MA, 2005.

Cross s2

Surface s2 Surface s6

Cross s6


High permeable membranes for dehydration of isopropanol by pervaporation

*Toraj Mohammadiazemimoghadam, KMansoorAmir Nouri, Mostafa Jafari,

Research Centre for Membrane Separation Processes, Faculty of Chemical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, Iran

Tel: +98 21 77240496, Fax: +98 21 77240495 *Corresponding author: E-mail address: [email protected] (T.Mohammadi)

1.Introduaction

Pervaporation (PV) is an attractiveseparation technique extremely in cases for which ordinary distillationis inapplicable, such as azeotropic mixtures, or mixturesof components having close boiling points [1–3]. Especially, PVdehydration of solvents including a small amount of water is energysaving in comparison with conventional distillation [3]. Zeolitemembraneshave recently offered significant potential for PV agent with highseparation factor and permeation flux together with high chemicaland thermal stability.In order to purify isopropanol (IPA) fromcleaning process in industries such as precision machinery andelectronics, and to dehydrate ethanol used in food industry, PV using NaA zeolite membraneshas been practically used [4–6].

2.Experimental

A-type zeolite membranes were formed by a seriesof hydrothermal reactions on the outer surfaces of theporous disksupports. Water glass, NaAlO2, NaOH, and waterwere used as starting materials, and NaA zeolite membrane samples were synthesized hydrothermally for 3 h at 100 over the surface of asymmetric supportsusinggel solutions of Al2O3:SiO2:Na2O:H2O= 1:2:3.4:155.Porous -alumina disksare used as support for the zeolite membranes.A secondary growth method including seeding synthesis was employed.After synthesis, the membrane was washedwith deionised water as many times as requiredto reduce the filtrate pH to less than 10, anddried at room temperature for a little while andthen dried in an oven at 100°C for 4–5 h toremove water from the zeolite crystals. Toprevent probable heat shocks, the rate at which temperature was increased/ decreased to/from 100°C was less than 0.5°C min–1.


SEM

The membrane cross-section was analyzed by Scanning Electron Microscopy (SEM). As observed in Figure 1,the membrane thickness is less than 4 micrometers.

Pervaporation

The as-synthesized NaA zeolite membranes were evaluated by pervaporation. The pervaporationperformance of membranes were determined by separation factor (α) and permeation flux (J). The membrane separation factor for component i over component j and permeation flux (J) were respectively defined as:

//

/ i ji j

i j

y yα x x

= .∆


where xi and xj are weight fractions of component i and component j for feed mixture; yi and yj are corresponding weight fractions in permeate; w is the total weight of permeate, kg; Δtis the collecting time, h; and A is the effective separation area of the membranes. The membranes showed water/isopropanol separation factor of more than 10,000 and water permeation flux of about 4 kg/(m2h) at 30using a feed of 30% (w/w) water in isopropanol.

Figure.1: SEM imageofNaA zeolite membrane synthesized over -alumina support

Reference [1] F. Lipnizki, R.W. Field, P.-K. Ten, Pervaporation-based hybrid process: a reviewof process design: applications and economics, J. Membrane. Sci. 153 (1999) 183.

[2] X. Feng, R.Y.M. Huang, Liquid separation bymembranepervaporation: a review,Ind. Eng. Chem. Res. 36 (1997) 1048.

[3] U. Sander, P. Soukup, Design and operation of a pervaporation plant for ethanoldehydration, J. Membrane. Sci. 36 (1988) 463.

[4] Y. Morigami, M. Kondo, J. Abe, H. Kita, K. Okamoto, The first large-scale pervaporation

plant using tubular-type module with zeolite NaA membrane, Sep.Purif. Technol. 25 (2001) 251.

[5] M. Kondo, T. Yamamura, T. Yukitake, Y. Matsuo, H. Kita, K. Okamoto, IPA purification for lens cleaning by vapor permeation using zeolite membrane, Sep.Purif. Technol. 32 (2003) 191.

[6] M.Kondo,H.Kita, Permeation mechanism through zeolite NaA and T-type membranes for practical dehydration of organic solvents, J.MembraneSci 361 (2010) 223.


Removal of Heavy Metal from Aqueous Solution by tetrakis(4-carboxyphenyl)Porphyrin-Functionalized SBA-15 Mesoporous Silica

RahmatollahRahimi*, Mehdi Deilamkamar,AhmadNajafian, Ali Maleki,MahboubehRabbani,

Chemistry Department, Iran University of Science and Technology, Tehran, 1684613114, Iran

*.Tel:+982177240290, Fax:+982177491204, [email protected]

1.Introduction

Among environmental problem, water pollution by heavy metals is a serious problem, which cause toxic effects on human health, animal and plant.Among various methods for removing heavy metals, the adsorption process is widely used because of its simplicity, relatively low cost, and high efficiency in removing heavy metal ions from wastewater.Porphyrins have employed as a ligand for the removal of metals due to the high removal efficiency and ligational properties. The nitrogen atoms in the tetrapyrrole ring act as ligational sites and also attract metal ions on account of their strong electron-donor properties. The ordered mesoporoussilicas have many advantages such as good accessibility to active site, rapid mass transport, and good hydrothermal stability.The use of homogeneous porphyrin has disadvantages which these disadvantages can be eliminate by encapsulating into inorganic supports. Moreover, immobilizationinto the supports, increase stability and selectivity of porphyrin and makes possible recycling and reuse.SBA-15 silica due to their large surface area and pore volume values is good candidate to be used as support for functionalization porphyrins.In this workwe successfully were studied immobilization of tetrakis(4-carboxyphenyl)porphyrin(TCPP) into SBA-15 and its efficiency this hybrid material in removal of heavy metal.

2.Experimental Amino-functionalized SBA-15 was synthesized by P123 and tetraethylorthosilicate as surfactant and silica source, respectively, then modified by aminopropyltriethoxysilane (APTES). In this study, TCPP was synthesized by Adler's method. Immobilization of TCPP into NH2-SBA-15 also was performed successfully. The characterization of synthesized materials were identified by FT-IR, UV-vis spectroscopy, XRD, nitrogen adsorption-desorption and SEM image.


3.Results and Discussion Fig. 1 shows scanning electron microscopy (SEM) image of NH2-SBA-15.This image reveals a short length channels and hexagonal disk-shape morphology. The SEM image also shows that the sample crystal structure is preserved, but the particle size after modifying by APTES is smaller compare to SBA-15. The UV-vis spectra of TCPP (Fig.2)shows a soret band at 417 nm and four weak Q-bands at 450-700 nm and confirmed that the porphyrin is synthesized successfully.

Fig.1. SEM image of NH2- SBA-15Fig.2.UV-Vis spectra of TCPP

Demetallation experiments was carried out by stirring TCPP-SBA-15 and metal solution at room temperature. The solution from each vial was analysed for metal ion concentration after different time intervals and removal rate of metal ion was calculated.

References

[1] E.Jeong, M.B.Ansari, Y.mo, S.park, Journal of hazardous materials 185. (2011) 1311–1317. [2] X.Xue, F.li, Journal of microprous and mesoporous materials116. (2008) 116–122. [3] Thiam-Leng Chew, Abdul L. Ahmad, Subhash Bhatia, Advances in Colloid and Interface Science 153. (2010) 43–57


Photocatalytic degradation of methylene blue with porphyrin-sensitized N, S-

codopedTiO2under visible light

S. SafalouMoghaddam, R. Rahimi*,M. Rabbani, A Najafian

Chemistry Department, Iran University of Science and Technology, Tehran, 1684613114, Iran

* Tel: +982177240290, Fax: +982177491204, [email protected]

1.Introduction

Dye-sensitized TiO2 is a process employed in many technologicalapplications (solar energy conversion, photocatalysis, photography and electro photography) because of its low potential cost, low environmental impact and efficient power conversion[1,2].The adsorbed on the surface of TiO2 can be excited by visible light. Then, the photoinduced electrons inject into the conduction band of TiO2, and further form .O2and .OH with O2 adsorbed on the surface of TiO2, leading to the oxidation of organic molecules. Obviously, the mechanism of dye sensitization to enhance the visible – light absorption and photocatalytic activity of TiO2 were different from N and Scodoping. It is deduced the coupling of N and S codoping with dye sensitization may be a good way to remarkably improve the visible – light absorption and photocatalyticeactivity of TiO2.

In the present investigation, Nand S codoping TiO2sensitized by tetrakis (4-carboxy phenyl)porphyrin (H2TCPP) and photocatalytic activity of sample s was evaluated by degradation rate of methylene blue under visible light irradiation.

2.Experimental

Photocatalyst(N, S)-codoped TiO2was synthesized through a straightforward method. In this method, nitrogen and sulfur doping was done by using ammonium sulfate as the modification agent of the titanium isopropoxide with (molar ratio 1:8, (TTIP: [(NH4)2SO4])). Dried mixture was calcined at temperature 850°C for 2h with 5°C/min ramp [3].Then N, S-codoped TiO2 modified with H2TCPP was prepared by mixing 1g of N, S-codoped TiO2and 0.05g of H2TCPP in DMF, and DMF was heated to reflux for five hours.after adsorbing H2TCPP,N, S-codoped TiO2was filtered, washed with DMF until the was colorless, then washed five times with DI water and dried at room temperature[4].


XRD pattern of catalyst indicated at Fig. 1 and displayed anatase phase TiO2 (2θ = 25.335°). N, S-codoped TiO2 nanoparticles sensitized by Tetra (4-carboxyphenyl) porphyrin,characterized by DRS and shifted absorption edge to the visible light region that can be observed for TCPP/N, S-codoped TiO2in comparison with N, S-codoped TiO2 and TiO2-P25 at Fig. 1.


Fig. 1. XRD pattern of (N, S)-codoped TiO2 and DRS Spectra of TCPP/N, S-codoped TiO2, N, S-codoped TiO2and TiO2-P25

The Photocatalytic activities for degradation of methylene blue under visible light using prepared N, S-codoped TiO2and TCPP/N, S-codopedTiO2Photocatalysts were tested. The result of photocatalytic degradation of methylene blue indicated that photocatalytic activity TCPP/N, S-codoped TiO2 was better than N, S-codoped TiO2 under visible light.

In this work,N, S-codoped TiO2was sensitized by H2TCPP for further response of TiO2. Due to the presence of carboxyl groups, H2TCPP can be chemisorbed on the surface of TiO2 through the O=C-O-Ti bonds. These bonds cannot only enhance the adsorption quantity of H2TCPP, but act as an electron transfer channel, facilitating the electron injection from excited H2TCPP molecules into conduction band of TiO2. In this investigationTCPP/N, S-codoped TiO2 exhibits higher photocatalytic activity than N, S-codoped TiO2under visible light, which can be attributed to the coupling effect of adsorbed dye and codoping N and S atoms.

References

[1]O Regan O, Gratzel M. Nature, 353. (1991), 737-740.

[2]SerponeN, Res ChemIntermd, 20, (1994), 20, 953-992.

[3] PradeepanPeriyat, Declan E. McCormack, Steven J. Hinder, Suresh C. Pillai, J. Phys. Chem. C. 113, (2009), 3246-3253.

[4]Di Li ,Wenjun Dong , Shangmei Sun, Zhan Shi, ShouhuaFeng, J. Phys. Chem. C. 112, (2008), 3246-3253.


Experimental design for the optimization of ammonium ion removal from

wastewater using natural Western Azarbaijan zeolite

Amir Khosravi a, b*, MajidEsmhosseinia, SomayehKhezria aDepartment of Chemistry, Faculty of Science, Urmia University, Urmia,57169-33111, Iran

b Environment radiological protection division, National radiation protectiondepartment,

Iranian nuclear regulatory authority, Tehran, 14155-4494, Iran.

*Corresponding author:Tel. :( +98)9123971596 fax. :( +98)2188678251

Email address:[email protected]

1.Introduction

Nitrogen compounds are undoubtedly considered as one of the most vital elements in living organism’s life. The presence of excess nitrogen compounds causes environmental pollution and leads to harmful toxic symptom and put the sea animal’s life particularly fishes in danger. Ammonia and ammonium ion are the more commonly polluting nitrogen compounds in wastewater and groundwater.

Clinoptilolite is the most abundant natural zeolite found in nature that has high affinity for adsorption some of cations such as ammonium ion.

Central composite design (CCD) and response surface methodology (RSM) were applied as experimental strategies for modeling and optimization of the values of some effective parameters on removal of inorganic compound such as ammonium ion from water and wastewater using ion exchangers like zeolite. Furthermore, the influences of interactions between parameters on the responses were well identified and by using an experimental design, the time and the number of tests were also optimized.In this study, the main purposes includes: (1) to investigate the potential of natural Western Azarbaijan zeolite for removal of ammonium ion from wastewater. (2) To evaluate application of zeolite as an ion exchanger material for the exclusion of ammonium ion from aqueous solution and to optimize the effective parameters in column systems.

2.Experimental

Ammonium ion exchange experiments were carried out using column with a diameter of 10 mm and height of 50 cm that was filled with fine zeolite (2.0 mm) and effects of flowrate, pH and initial ammonium concentration on the ammonium removal efficiency of zeolite were investigated.

Essential Regression and Experimental design for chemists and Engineers (EREGRESS), as a MS Excel Add-in software, was used to design the experiments and to model and analyze the results.

Central composite design (CCD) was used to optimize the experimental variables. Three independent factors, namely the initial ammonium concentration (F1), flow rate (F2) and pH (F3) were studied at five levels with four repeats at the central point, using a circumscribed central composite design.

The cation exchange capacity (CEC) is a key characteristic of zeolite when it’s applied in adsorption of cations such as ammonium ion. The CEC indicates the amount of cations should be accommodated by zeolite. To determine CEC, a Flame photometer (Corning Co., U.K) was used via analyzing sodium ion concentration residual in the potassium chloride solution 3.Results and discussion

The absorbance of samples in maximum wavelength (640 nm) were collected as responses in order to


optimize three independent factors in column method, namely initial ammonium concentration (F1), flow rate (F2) and pH (F3). The purpose of this CCD strategy were: (1) study of the effect of initial ammonium concentration, flow rate and pH on removal efficiency of ammonium ion from synthetic solution in column method; (2) to calculate optimum amount of the effective variables that have a higher impact on removal efficiency and illustration of interactions between effective parameters.

Fig1. Response surface of initial ammonium concentration (Conc.) (F1), flow rate (F2) and pH (F3)

Optimum conditions can be selected from the obtained model for further examinations (Table.1).

Table1: Optimum conditions obtained by response surface modeling for ammonium

removalfromsolutionby ion exchange in column method

Variable name Optimum values Selected values F1 Initial ammonium concentration ( mg l-1) 28-33 30 F2 Flowrate (ml min-1) 1-1.2 1 F3 pH 5.7-6.8 6

In this study, cation exchange capacity of natural WesternAzarbajan zeolite was determined to be

approximately 1.79 meq g-1.It was demonstrated that the cation exchange capacity of the natural zeolite was strongly related to its structural characteristic, nature of cation and its concentration in solution. Conclusions The following are important points that can be concludedfrom the results obtained in this study:

Natural Western Azarbijan zeolite has an excellent potential to be used as effective and low cost adsorbent for ammonium ion removal from aqueous solution.

The pH value of the aqueous solution is an important controlling parameter in the adsorption and ion exchange process that significantly is influenced on ammonium removal efficiency.

As the initial ammonium concentration increases selectivity of the zeolite samples for removal of ammonium ions from aqueous solutions increases

By using central composite design (CCD) and subsequently response surface methodology, the effect of parameters such as initial ammonium concentration, pH and flow rate on removal efficiency of ammonium in column method was studied and the optimum conditions were obtained. Also, the possible interactions between these effective parameters were shown.

Key References [1] I. Burlacov, J. Jirkovsky, M. Muller and R.B. Heimann, Surf. Coat. Technol. 201(2006), 255-264. [2] Q. Du, S. Liu, Z. Cao, Y. Wang, Sep. Purif. Technol. 44(2005), 229-234. [3] A. Dimirkou, M. K. Doula, Desalination. 224(2008), 280-292. [4] M. Sarioglu, Sep. Purif. Technol. 41(2005), 1-11.

1.0

22.844.6

0.00

0.05

0.10

0.15

4.0 5.1 6.2 7.3 8.4

Conc

Abs

orba

nce

pH

4.06.2

8.40.00

0.05

0.10

0.15

1.0 1.4 1.9 2.3 2.8

pH

Abs

orba

nce

Flowrate


Use of raw bentonite for adsorption of 2-picoline from aqueous solutions

SaeedehHashemian, S.MiojtabaModaress Islamic Azad University, Yazd branch, Chemistry department, Iran, Yazd

Corresponding author. Tel: 098 351 8117572) Fax: 098 3516240020

E-mail address: [email protected] 1. Introduction

2pic is a colorless liquid and has an unpleasant odor similar to pyridine. It is also used as a solvent and a raw material for various chemicals used in the manufacture of various polymers, textiles, fuels, agrochemicals and colorants. 2-pic is considered to be a hazardous chemical. Various industrial units manufacturing pyridine and its derivatives, pharmaceutical units, etc. discharge 2pic-bearing wastewaters [1]. Various physic-chemical and biological treatment techniques are suggested for the treatment of 2-pic-bearing wastewaters, which include concentration followed by biodegradation [2] and adsorption [3-5]. Adsorption can be a preferred treatment technique, provided that the adsorption process is cost-effective.

Natural clays are low-cost and readily available materials functioning as excellent cation exchangers. The adsorption capacity of clays results from a relatively high surface area and a net negative charge on their structure, which attracts and holds cations such as heavy metals [6-8].

2. Experimental

The raw bentonite was prepared fropm mine in Yazd(IRAN). The collected samples were washed repeatedly with deionized water to remove extraneous materials and salts. The sorbents then dried in an oven at 150°C for 24 h. 2-picoline was purchased from Merck and used without further purification. The standard solutions of 1000 mg L-1 of 2-pic was prepared as stock solutions and subsequently whenever necessary, diluted. 3. Results and discussion 3.1. Characterization of composite The characterization of rawbentonite from XRD is shown on Table 1. This is a very interesting characteristic for removing of dye. Table 1 indicates the presence of silica and alumina as major constituents along with traces of sodium, potassium, iron, magnesium, calcium and titanium oxides in the form of impurities. XRD also indicated the presence of free quartz bentonite. It is, thus, expected that the adsorbate species will be removed mainly by SiO2 and Al2O3.Fig.1 has shown the XRD pattern of raw bentonite.

Fig. 1: the powder X-ray diffraction of raw bentonite


0

100

200

300

400

500

600

0 30 60 90 120 150 180

qe

(mg

g¯¹)

t (min)

Table 1The characterization of rawbentonite from XRD

3. 2.Effect of contact time The effect of contact time on the removal 2-pic by raw bentonite for 0.1g bentonite and 30 mL of 2-pic 50 mg L-1 is shown in Fig. 2. The Fig shows rapid adsorption of 2-pic initially up to 10 min. The result shows the contact time needed for 2-pic to reach equilibrium was 15 min. It can be seen from Fig. 2, the amount of the absorbed 2-pic onto bentonite initially, increase with time and, at some point of time, it reaches a constant value beyond which no more is removed from solution. The amount of 2-pic adsorbed at the equilibrium time reflects the maximum adsorption capacity of the adsorbent under those operating conditions. It is evident that the bentonite is efficient in absorbing equilibrium gradually. 411a`ybgfdsaRE

Fig. 2. Effect of Contact time on the removal of 2-pic by raw bentonite 2.3. Effect of pH The effect of pH on adsorption of 2-Picoline ontobentonitewas studied by varying the pH of solution from 2-12. It is very important, that the change of pH has not effect on the removal of 2-Picoline. The adsorption of 2-Picoline was done on all of pHs. References [1] V.C. Srivastava, I.D. Mall, I.M. Mishra, J. Hazard.Mater. 134 (1-3) (2006) 257-267. [2] G.K. Sims, L.E. Sommers, Environ. Toxicol. Chem. 5 (1986) 503-510. [3] D.H. Lataye, I.M. Mishra, I.D. Mall, J. Environ. Eng. (2011) in press. [4] D. Mohan, K.P. Singh, S. Sinha, D. Gosh, Carbon 43 (2005) 1680-1693. [5] D. Mohan, K.P. Singh, D. Ghosh, Environ. Sci. Technol. 39 (13) (2005) 5076-5086. [6] S. Hashemian, Main Group Chemistry, 6 (2) (2007) 97-107. [7] Z. Bouberka, S. Kacha, M. Kameche, S. Elmalah, Z. Derriche, J. Hazard.Mater.B 119 (2005) 117-124. [8]S. Hashemian, African J. Biotechnol. 9 (50) (2010) 8667-8671.

Weight % Component 63.91 SiO2 13.8 Al2O3 3.52 MgO 2.67 Fe2O3 1.21 CaO 1.79 Na2O 2.11 K2O 11.37 LOI 0.07 SO3


Study of adsorption of indigo carmine dye by natural clay

Saeedeh Hashemian11, SamanSadri1 1-Islamic Azad University, Yazd branch, Chemistry department, Iran, Yazd

Corresponding author. Tel: 098 351 8117572) Fax: 098 3516240020

E-mail address: [email protected]

1. Introduction Indigo carmine is generated as a highly toxic dye, which may lead to tumors at the site of application, cause skin or eye irritation and can be fatal if consumed. There are several methods applicable for the reclamation of dyeing wastewaters. These techniques are coagulation and flocculation [1], adsorption [2], ozonation [3], membrane [4], electrochemical [5]. Adsorption can be a preferred treatment technique, provided that the adsorption process is cost-effective.

Natural clays are low-cost and readily available materials functioning as excellent cation exchangers. The adsorption capacity of clays results from a relatively high surface area and a net negative charge on their structure, which attracts and holds cations such as heavy metals [6-8].

2. Experimental Indigo carmine (IC) dye was purchased from Merck and used without further purification. IC has C16H8N2Na2O8S2 formula. Chemical structure of IC is shown in Fig. 1. It has a molecular weight of 466.36 g mol-1. The standard dye solutions of 1000 mg L-1 was prepared as stock solutions and subsequently whenever necessary, diluted.The raw bentonite was prepared fropm mine in Yazd(IRAN). The collected samples were washed repeatedly with deionized water to remove extraneous materials and salts. The sorbents then dried in an oven at 150°C for 24 h.

Fig 1. Molecular structure of indigo carmine

3. Results and discussion 3.1. Characterization of composite The characterization of rawbentonite from XRD is shown on Table 1. This is a very interesting characteristic for removing of dye. Table 1 indicates the presence of silica and alumina as major constituents along with traces of sodium, potassium, iron, magnesium, calcium and titanium oxides in the form of impurities. XRD also indicated the presence of free quartz bentonite. It is, thus, expected that the adsorbate species will be removed mainly by SiO2 and Al2O3.Fig. 2 has shown the XRD pattern of raw bentonite.


Table 1The characterization of rawbentonite from XRD

2.3. Effect of pH Fig. 3 is shown the % sorption of IC by natural bentonite at different pH. The graph clearly indicates that the sorption process is strongly pH dependent and the maximum uptake of the dye occurs at pH 2. Thus, the pH 2 was selected as optimum pH for following study. The reduction of IC removal in higher pH may be due to the increase of repulsive force between the functional groups on the surface of sawdust and IC, which exists mainly as anion form at higher pH, and thus reduces the sorption of IC onto the surface of the bentonite clay.

Fig 3. Effect of pH on the removal of IC onto natural bentonite Reffereces [1] E. Guibal, J. Roussy, Coagulation and flocculation of dye-containing solutions using a biopolymer (Chitosan), J. React. Funct. Pol. 67 (2007) 33-42. [2] M.K. Purkait, A. Maity, Removal of cango red using activated carbon it's regeneration, J. Hazard.Mater. 145 (2007) 287-295. [3] J. Chen, L. Zhu, Catalytic degradiation of orange II by UV-Fenton with hydroxyl-Fe-pillared bentonite in water, Chemosphere 65 (2006) 1249-1255. . [4] R. Sary, A. Hafez, M. khedr, A. El-Hassanin, Removal of lead by an emulsion liquid membrane, J. Desalination, 212 (2007) 165-175. [5] L. Gomes. D.W. Miwa, G.R.P. Malpass, A.J. Motheo, Electrochemical degradation of the dye reactive orange 16 using electrochemical flow-cell, J. Braz. Chem. Soc. 22 (7 )( 2011) 223-229. [6] S. Hashemian, Main Group Chemistry, 6 (2) (2007) 97-107. [7] Z. Bouberka, S. Kacha, M. Kameche, S. Elmalah, Z. Derriche, J. Hazard. Mater. B 119 (2005) 117-124. [8]S. Hashemian, African J. Biotechnol. 9 (50) (2010) 8667-8671.

80

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Weight % Component 63.91 SiO2 13.8 Al2O3 3.52 MgO 2.67 Fe2O3 1.21 CaO 1.79 Na2O 2.11 K2O 11.37 LOI 0.07 SO3


A Simple Method for the Synthesis of 2-ArBenzimidazoles by Nano-CuY Zeolite as an Efficient Catalyst

NooshinKhodaparasta, Mehdi Kalhora* aDepartment of Chemistry, Payame Noor University, Tehran 19395-4697, I. R. of Iran

*E-mail: [email protected]

1.Introduction

The substituted benzimidazoles have commercial applications in veterinarian medicine as anti-helminthic agentsand in diverse human therapeutic areas such as treatmentof ulcers and as antihistaminic [1]. Recently, ithas been found that two groups of benzimidazoles,namely the 5,6-dinitro and 2-trifiuoromethyl derivativesto be promising candidates for antimicrobial drugs [2].Several methods have reported for the synthesis of these compounds including the reaction of carboxylic acids or their derivatives (nitriles, orthoesters, imidates) with o-phenylenediamines, and the reaction of o-phenylenediamines with aldehydes in the presence of an acid catalyst under various reaction conditions [3-5].However, the most of these methods have some limitations including harsh reaction conditions, low yields, long reaction times, high temperature, use of unavailable catalyst and tedious workup procedure. Consequently, the introduction of new methods and/or further work on technical improvements to overcome these limitations is still needed. Recently, synthesis of organic compounds in the presence of heterogeneous or homogeneous catalysts has attracted special interest as they have many advantages such as availability, ease of handling and easy workup.

On the other hand, Zeolites are crystalline hydrated aluminosilicates ofthe alkaline earths. It is well known that the acidic sitesof zeolite can be catalyzed organic reactions [4]. Theacidity of the zeolite could be due to Bronsted andLewis sites [6].Furthermore, the exchange of acidic zeolite sites with Cu, Fe, Co, Mn and Zn cations has increased Lewis sites and consequently, catalytic activity of zeolite [9].

In view of these points and as a part of our interest researches on the development of new methods for the synthesis of benzimidazoles, we wish to report a clean and facile synthetic procedure for preparation of 2-substituted benzimidazoles using transition metal/Zeolite as efficient nano-catalysts.

2.Experimental

General Preparation of 2-Arylbenzimidazoles. To a solution of o-phenylenediamine (0.1gr, 0.9 mmol) in ethanol(20 mL), appropriate aromatic aldehyde (0.9 mmol) andnano-CuY Zeolite [7] (0.001 g) was added. The reaction mixture was stirredat room temperature for 8 min. The used catalyst was collectedby filtration. Then water (100 mL) was added to the filtrationand the precipitate filtered off and then washed with a mixtureof water and ethanol (3:1). The crude product was recrystallizedfrom benzene or dichloromethane.

2-Phenyl-1H-benzimidazole (3a)White crystals, mp: 286–2888C. IR (KBr, max): 3348 (NH),3047 (CH aromatic), 1462 (C=C). 1H NMR (acetone-d6): (ppm) δ 7.56–8.24 (m, 9H, aromatic), 11.85 (bs, 1H, NH). Anal cald for C13H10N2: C, 80.39; H, 5.19; N, 14.42%.Found: C, 80.50; H, 5.38; N, 14.56%.


3.Results and Discussion Firstly, a convenient synthetic method for the synthesis of 2-arylbenzinidazoles at room temperature was sought. Then, to evaluate the catalytic efficiency of the metals nitrate, the reaction of o-phenylenediamine and p-nitrobenzaldehyde was carried at presence of the catalyst 2W%, Nano-CuY Zeolite in ethanol. For optimization the amount of catalyst, this reaction as a model was used under the same conditions. The optimum amount of Nano-CuY Zeolitecatalyst for the period of 8 min reaction was 1W% of o-phenylenediamine. The amount of catalyst over 1W% did not improve the yield of the product.To examine the effect of solvent, the reaction was carried out in some organic solvents at room temperature with 1W% of catalyst for 8 min. The results showed that EtOHis suitable solvent for our procedure.

To study the development and generality of this simple method, the optimized procedure was extended for preparation of several benzimidazoles (Scheme 1).

+

N-CuY Zeolite

rt, C2H5OH

21 3a-n

NH2

NH2

Ar CHON

HN

R

3a: R=H 3h: R=4-NO23b: R=4-Br 3i: R=4-Me3c: R=2-Cl 3j: R=4-OMe3d: R=3-Cl 3k: R= 3-OMe, 4-OMe3e: R=4-Cl 3l: R=2-OH3f: R=2-NO2 3m: R= 2-OH, 5-Br3g: R=3-NO2 3n: R= 2-OH, 4-OMe

Scheme 1 On the other hand, the reactions with CuY Zeoliteas a catalyst were also examinedunder same experimental conditions. Theresults obtained from a condensation reactionof aldehydes ando-phenylenediamine underthe optimized conditions were compared withthe ones obtained using nano-CuY Zeoliteas a catalyst, and the data showed that the nano-CuY Zeolite was a fairly better catalyst for this reaction than CuY Zeolite orNaYZeolite [4].

References:

[1] A. A. Spasov,I. N. Yozhitsa, L. I. Bugaeva, V. A. Anisimova,Pharm. Chem. J. 33 (1999), 232–243.

[2] J. Z. Stefanska, R. Gralewska, B. J. Starosciak, Z. Kazimierczuk, Pharmazie 54 (1999), 879.

[3] (a) P. Salehi, M.Dabiri, M. A.Zolfigol, S. Otokesh, M. Baghbanzadeh,Tetrahedron Lett., 47(2006), 2557-2560; (b) M. Shen, C. Cai, J. Fluorine Chem., 128(2007), 232-235.

[4] A. Mobinikhaledi, N. Foroughifar, M. Zendehdel, M. Jabbarpour,Syn. Reac. Inorg. Met-org. Chem., 38 (2008), 390-393.

[5] (a) X. Han, Ma H., Y. Wang,Russ. J. Org. Chem.(2008), 863-865; (b) K. H. Bûchel,Z. Naturforsch, 25B (1970), 934-944.

[6] J. M. Thomas, C. R. A. Catlow, Prog. Inorg. Chem. 35 (1987), 1.

[7] M. Zendehdel, A. Mobinikhaledi, F. H. Jamshidi, J. Incl. Phenom. Macrocycl. Chem. 59 (2007), 41–44.


Prevention of acute ammonia toxicity in bluga (Huso huso), using natural zeolite

Farhangi, M* Gonbad Kavous University

*Corresponding Author Email: [email protected]

1.Introduction:

Ammonia is one of the most toxic metals to aquatic organism and ecosystems. Ammonia appears

to have a direct effect on the growth of aquatic animals (Colt 2006)and it causes a decrease growth,

disease resistance (Lemarie´ et al 2004) or even cause fish mortality in intensive culture. (Wang et al

2000). However, the concentration of these elements above tolerable levels is a disturbant factor for

species survival and ecosystem stability. The toxic effect of trace metals is influenced by environmental

factors such as salinity, pH, water hardness and temperature (Lemus &Hung 1999). All fishes are

sensitive to minor fluctuations of ammonia compounds. Zeolites are used as a natural material to remove

ammonia. One of the best zeolites for ammonia removal is clinoptilolite (Bergero et al 1994).

Clinoptilolite has been found very effective in removing ammonia from water by means of its excellent

ion exchange capacity since the seventies of last century (Wang et al., 2000). Recently, it has been used in

detergents, aquaculture ponds and nuclear treatment, but it also has large potentials for other applications

in liquid waste treatment (James et al 2000). This research tried to determine lethal concentration (LC96)

of ammonia on beluga sturgeon (Hsuo huso) (Linneaus,1758) and survey the effects of clinoptilolite

zeolite on the removal of ammonia compounds from water environment.

2.Material and methods:

fish selection: This study was carried out in the Laboratories of Department of Natural Resources

of Gonbad University. Fry ofH. huso with an average weight and length 465g and 224cm respectivly were collected from Sijaval Fish Culture Center. The experiments were done during spring 2010. After collection, fish were acclimated to laboratory conditions for one week. They were kept in glass fiber tanks filled with 300 L of fresh water (under constant aeration, fixed temperature =26ºC and pH =8.2). The experiments were done by Water Static Method during 96h (Sprague 1969).Air-stone has been used in treatment as an aerator.Determination of LC50: In first, five flasks of 35 liters each were used with concentrations of 0, 15, 30, 50 and 75 mgL-1 of ammonia (prepared with NH4Cl). A control without addition of ammonia in the water was also tested. Fifteen fish were placed in each flask, with their respective duplicates, for a 96 hours exposition period. The amount of ammonium chloride salt to be added in each aquarium was calculated after the volume of each aquarium was accurately determined. Observations were made at intervals of 24, 48, 72 and 96 hours respectively. Fish were not fed during this period.


Percent of mortality was registered every 24 hours. Then fish dead were collected. Zeolite efficiency Test: At first, a substantial amount of ammonia in the water was measured and then in each basin some ammonia salt equivalent to 50 mgL-1 was added according to preliminary test. Granulated zeolite at 3 treatments of 5, 10, 15 gL-1 with three replications for each treatment was used. Then at the end of the test, every 12 hours, the amount of ammonia from the water basin was measured.The behavioral changes of the healthy fish and the fish exposed to various doses of ammonia wererecorded.Samples were randomly taken from gill, kidney and liver of fish and histopathological sections were prepared.Statistical Analysis:Comparisons of mean values were performed using one-way analysis of variance (ANOVA) followed by the Duncan’s test. In all cases, the significance level adopted was 95%. 3.Result and discussion

The research was accomplished in order to study of the efficiency natural zeolite to prevent acute toxicity

of ammonia to Huso huso. The study was performed using Water Static Method during 96 hours. Fish

with average weight 465 g and total length 224 cm were exposed to four different concentrations (15,

30, 50, 75 mgL-1) of ammonia salt. A group of fish was considered as control. Under of stable condition,

the lethal concentration of ionized ammonia was 50mgL-1 during 96 hours. In the lethal concentration of

total ammonia different amount of 5, 10, 15 gL-1 granulated clinoptilolite zeolite were used. Results

indicate significant differences between treatments and also with control (p<0.05). With increasing

clinoptilolite zeolite in each treatment, the survival rate of fish also increased significantly (p<0.05). In

lethal concentration of ammonia, the use of 15gL-1 zeolite could prevent the mortality rate.

Histopathological findings were showed that major lesions were hemorrhage, hyperemia, hyperplasia,

epithelial cells necrosis, degenerated tubules of kidney, expansion of Bowman's capsule and hepatocytes

necrosis.

Figure 1. Histograms based on Fish survival in different dosage of ammonia

020406080

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Figure 2. Linear regression based on Fish mortality in different dosage of ammonia

Figure 3- Decreasing the ammonia (NH3) concentration during 96 h

Refrences:

1- Abdullah S, and Muhammad J., 2006 Studies on acute toxicity of metals to the fish, Catla catla. Pakistan Journal of Biology Sciences. 9,9: 1807-1811.

2- Bergero D., Boccignone M., Palmegiano G.B.,1994 Ammonia removal capacity of European natural zeolite tuffs: Application to aquaculture waste water. Aquaculture and fisheries 25:81-86.

3- Colt J., 2006 Water quality requirements for reuse systems. Aquacultural engineering 34: 143-156.

4- Farhangi M., Hajimoradloo A.M., 2008 The study of clinical signs of acute toxicity by ammonia on rainbow trout (Oncorhynchus mykiss). The first national conference on the Caspian Sea fisheries resources. 9-10 November, Gorgan, Iran.

5- Farhangi M., 2010 In vitro, Determination of LC5096h of znso4 on common carp (Cyprinus carpio). 2nd International congress on aquatic animal health management and disease, 26-27October, Tehran- Iran.

6- Giguere A., Campbell P.G.C., HareL., McDonald D.G., Rasmussen J.B., 2004 Influence of lake chemistry and fish age on cadmium , copper, zinc concenterations in various organs of indigenous yellow perch (perca flavescens). Can. Fish. Aqua. Sci, 61: 1702-1716.

7- Gul A., Yilmaz M., Isilak Z., 2009 Acute Toxicity of Zinc Sulphate (ZnSO4.H2O) to Guppies (Poecilia reticulate). Journal of Science, 22, 2: 59-65.

8- James R., Sampath K., Selvanami P., 2000 Effect of Ion-Exchanging Agent, Zeolite on Removal of Copper in Water and Improvement of Growth in Oreochromismossambicus. Asian Fisheries Science 13: 317-325.

y = 1.5455x + 4.9966R² = 0.9341

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Concentration of ammonia mgL-1

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In vitro, thecomparison of Natural Zeolite and Nano – zeolite to absorb ammoniato rainbow

trout(Oncorhynchusmykiss).

aMahan Salamroodi, * Mohammad Farhangib;

b* GonbadKavousUniversity, Iran. aGuilanUniversity, Iran.

*Corresponding author: o9111789636, [email protected] 1.Introduction: One of the best materials for removing of ammonia compounds from water ambient is zeolite Natural resins, such as zeolite, are used in removing ammonia from wastewater culture systems (Boranic2001). They are further characterized by ability to loss and gain water reversibly and to exchange some of their constituent elements like Na+ and K+ with ammonium ion without major change of structure (Mumptoand Fishman 1977). The adsorption characteristics of any zeolite are dependent upon the detailed chemical-structural makeup of the adsorbent (Ackley,2003). Recently, application of Nano- zeolite is important. The Nano- zeolite is a kind of clinoptilolite that prepared after processing on natural clinoptilolite. Innature, these charges were satisfied by attractionof cat ions from the surroundings (Keith, 1981). However, thecat ions on Nano -zeolite readily exchange with othercat ions. Recently, it has been used in detergents, aquaculture ponds and nuclear treatment, but it also has large potentials for other applications in liquid waste treatment (James et al. 2000). This research tried to preventacute toxicity of ammonia compounds on rainbow trout by Nano- zeolite and Natural Zeolite. 2.Experimental The testing carried out in Ramsar fish culturing center, north Iran. Experimental fish was in the weight of 524 g and total length of 213 cm. Temperature, pH and dissolved oxygen in all experiments was stable at 20 ± 0.5 ºC , 8.4 and 9 ppm, respectively. Ammonia Concentration was produced by adding ammonium chloride (NH4-Cl) to water (Merck Co., Germany). Total ammonia concentrations were measuring with colorimeter DR/890 (Hach, USA). 15 fishes were placed in basin with 35 liters capacity.All tests were conducted to static water method during 24hours.Lethal concentration of total ammonia was based on initialexperimental (reported by Farhangi et al., 2002).So, fish mortality was appeared after 24h. Agroup of fish was as a control. After 24 hours, Total ammonia (N-NH4) was determined with a spectorophotometric method. Air-stone has been used in treatment as an aerator. The Clinoptilolite zeolite was used as Nano – zeolite. Initially the amount of substantial ammonia in the water was measured by photometric method and then each aquarium contained 25 mg/lit ammonia salt according to preliminary test. Nano- Zeolite was applied from Gharehyazi Company. For preparation of nano zeolite, they were located in 10 % sodium chloride solution at a temperature of 90 ºC for 30 minutes and then washed with distilled water, and finally were dried at 60 ºC for 1 hour (Wang et al. 2005). Nano-zeolites at dosages of 1, 3, 5, 7, 8 g/l were used with three replications. Until the end of study, the amount of ammonia in the water was measured by the4hours intervals in each step. All behavioral activity and mortality of fish was recorded during tests. Agroup of fish was placed in lethal concentration as a control.Samples were taken from gill of fish and histopathological sections were prepared.Data were analyzed by one-way analysis of variance (ANOVA) followed by Duncan multiple range test. All data are expressed as mean ± SD. The significance of results was at 5%. 3.Results and discussion The mortality rates was observedin lethal concentration (25mg/lit)after 24 hours. High mortality rates were observed in the early hours of exposure.In first treatment as control treatment no mortality was observed. Ammonia measured in each treatment at the end of the preliminary stage that was equivalent to the initial amount. Some behavioral symptoms such as gasping, swallowing water, the curvature of muscles, hit the basin sides, lack of balance and severe reaction to external factors were observed in


fishes and over time, sat on the floor of the basins while resting back and eventually died. Nano zeolite used in the main test effectively reduced ammonia in the water. Most absorption of ammonia in the first 4 hours after the start of testing was recorded. Eventually, the absorption rate of ammonia by nano zeolite treatments with increasing nanozeolite considerably increased. Most value of ammonia absorbed in the fourth treatment with 7 g/lit zeolite. Results indicate significant differences between treatments with each other and also control (p<0.05). With increasing nano zeolite amount in each treatment, the survival rate of fish also increased significantly (p<0.05). Fish survival rates were 0, 32, 45, 88 and 100 % in the main test treatments, respectively (fig.1).Figure 2 indicates decreasing ionized ammonium after 24 h in the main test treatments.

Fig. 1- Fish survival rate at different ammonia concentrationsFig.2-Decreasing the ammonium (NH4

+) concentration during 24 h Ammonium levels in treatments after 4 hours reduced from 25 mg/lit to 17, 13, 11, 9 mg/lit, respectively; and after 24 hours, process of absorption ammonium greatly reduced in all treatments.The fourth treatment showed highest rate of ammonium absorption relative to other treatments (fig.2). After a specific time, the rate of absorption depends on the amount of nanozeolite with decreasing usage in each treatments were reduced.During the trial fishes showed many behavioral severe reactions like disquiet and spasm. The studied of histological samples show that, The common lesions of fish gill exposed to ammonia lethal concentration like hyperplasia, edema, hyperemia, hemorrhage, expansion of secondary lamella, epithelial cells necrosis of gill and inflammation were showed(fig.3.4.5).

Fig.3-Gill histological sections that exposure to ammonia lethal concentration. Arrows shows distention of secondary lamella (* 200).

Fig.4-Gill histological sections that exposure to ammonia lethal concentration. Arrows shows edema in

Secondary lamella (* 400).

Fig.5-Gill histological sections that exposure to ammonia lethal concentration. Arrows shows hyperemia (* 400).

The lethal concentration of ammonium was equal to 25 mg/l in this experiment. In same experiments the 48h-LC50 was 59.4 mg/l of N-NH4 (0.34 mg/l of N-NH3) for smolts salmon (Knoph 1996). The lethal

013.3

3

33.33

73.33

93.33

100y

=0

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0

Fish

surv

ival

rate

nano zeolite at

Series1

0

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0 4 8 12 16 20 24

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concentration in varieties of fishes is different and depends to species, age and environmental factors in water. No data is about Nano – zeolite and acute toxicity on fish. In the trial, Nano- zeolite was able to make a considerable reduction of the lethal concentration of ammonia from 25 mg/l to 5.0 mg/l.While about 65 % of total ammonia in first 4 h were removed.According to Peyghan findings (1999) application of 10 g/l of zeolite concentration could prevent carp mortality at lethal concentration of total ammonia (150 mg/l) after 24 hours.Farhangi et al.(2002) reported, application of 15g/l of zeolite concentration could prevent % mortality at lethal concentration of total ammonia (25 mg/l) after 24 hours to rainbow trout.In laboratorial conditions the concentrations of NH3-N without any fishes were reduced from 27 to 3 mg/l at a retention time of 38 min (Miladinovica and weatherleyb 2008). Survival rates in rainbow trout by adding of nano zeolite were increased (fig1.). Application of Nano-zeolite has directly associated to removal of ammonia compounds. This ability to absorbing ammonia by using the Nano- zeolite after some time depending on the amount of Nano- zeolite for remove ammonia compounds were improved and during decrease ammonia in treatments, the zeolites reached to saturation point and not being able to continue the absorbing of this compounds. Just like in main test (fig. 2) .However that was saturated after about 16 h. Absorption speed rate considerably decreased after saturation zeolite.The present experiments show, addition of NH4Cl salt to trials as lethal concentration of ammonia causes to appear some nominal signs on fish behavior. So, the experiments showed at high ammonia concentration signs were happened such as slowly gill ventilation, air gulping, bending muscles, increase of opercular and buccal movement and hyper excitability. Similar results were also obtained by Farhangi et al. (2002), Knoph (1996) and Peyghan (1999). Actually, ammonia acts as a toxin and a stressor (FriasEspericueta 1999). This lesion was observed to form distension of secondary lamella, edema and hyperemia in fish gills. Most lesions in gills showed in the chloride cells that located in base of secondary lamellas and have ionic exchange duty for fishes. When ammonia increased in water ambient of fish, effluence this solution from fish body to water exists happened hardly. Ammonia toxicity emanated from concentration of the unionized ammonia because of its capability to move across all cells. Application of 7g/l Nano- zeolite reduced mortality rate after 24h. So, mortality percentage of fish was o after 24h in lethal concentration. Application Nano-zeolite to reduce ammonia toxicity on fish was demonstrated. While, there was application of 15g/l clinoptilolite zeolite to prevent mortality of rainbow trout by Farhangi et al, 2002. This means, Nano- zeolite is more effective.Consequently, using a particular amount of Nano- zeolite for prevention of ammonia compounds could be advisable. Hence, it seems that the zeolite is able to effectively remove the ammonia compounds but this absorption rate is relatively dependent to kind and quantity of nano zeolite. References

1- Ackley MW, Rege SU, and Saxena H. Application of natural zeolites in the purification and separation of gases. Microporous and Mesoporous Materials. 2003; 61: 25–42.

2- Boranic M. The effect of the zeolite clinoptilolite on serum chemistry and hematopoiesis in mice. Food and Chemical Toxicology. 2001; 39(7):717-727.

3- Farhangi M,HajimoradlooAM., and Kamali A. The efficiency of natural Zeolite to decrease toxicity of ammonia in rainbow trout (Oncorhynchusmykiss). Agriculture Sciences and Natural Resources Journal. 2002; 2: 195-203.

4- FriasEspericueta MG. Acute toxicity of ammonia to juvenile shrimp penaeusvannamei Boon. Bulletin of Environmental contamination and toxicology. 1999; 62:646-652.

5- James R, Sampath K, and Selvanami P. Effect of Ion-Exchanging Agent, Zeolite on Removal of Copper in Water and Improvement of Growth in Oreochromismossambicus. Asian Fisheries Science. 2000; 13: 317-325.

6- KeithF. The Encyclopedia of mineralogy. Hutchinson Ross publishing company.1981; 523-530. 7- Knoph M.B. Gill ventilation frequency and mortality of Atlantic salmon (salmosalar) exposed to

higher ammonia levels in seawater. Water Research oxford. 1996; 30:837-842. 8- Miladinovica N, and Weatherleyb LR. Intensification of ammonia removal in a combined ion-

exchange and nitrification column. Chemical Engineering journal. 2008; 135(1-2):15-24. 9- MumptoFA, and Fishman PH. The application of natural zeolites in animal science and

aquaculture. J. Animal Sciences. 1977; 45:1188-1203.


10- Peyghan R. Study of experiential of acute toxicity by ammonia in common carp (Cyprinuscarpio) based on histopathological changes and serum enzymes and possibility of prevent it by zeolite. Dissertation of Aquatic Animal Health Management and Diseases. Tehran University.PhD Thesis.1999; 104p.

11- Wang Y,and Walsh PJ. High ammonia tolerance in fishes of the family Batrachoididae (Toadfish and Midshipmen). Aquatic Toxicology. 2000; 50: 205-219.


Preparation of iminodiacetice acid functionalized mesoporous Carbone

And its application as sorbent for Removal of As (III), Pb(II), Cd(II) from waste water

aMandegarzadS. ,b*M. Anbia,aehghan.DR

a Research Laboratory of Advanced Materials, Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Tehran, Iran

b Research Laboratory of Nanoporous Materials, Faculty of Chemistry, Iran University of Science and Technology, Farjam Street, Narmak, Tehran 16846, Iran

*Tel. 982177491204; Fax 982177491204; email: [email protected]

1.Introduction The presence of heavy metal ions in the environment in general, Cadmium, lead and arsenic is one of the concerns due to their toxicity to many life forms. The methods used to remove of heavy metal ions are chemical precipitation, ion exchange, coagulation, flocculation, complexation, membrane process and sorption-chelate formation.[1]Among these methods, adsorption is still the most

versatile and widely used.The development of porous materials with large surface

areas is currently an area of extensive research, particularly with regard to

potential applications as environmental remediationRecently, the synthesis of

ordered mesoporous carbons (OMC) using ordered mesoporous silica( OMS) as hard

templates has attracted a great deal of attention. .Adsorption capacity of mesoporous carbon materials depends on the characteristics of mesoporous carbon such as texture (surface area pore size distribution)and surface chemistry (surface functional groups)[2].To enhance adsorption efficiency the surface of adsorbent is modified and it making them capable of adsorbing at the interfaces between liquid, solids and gases. Many chelaingagente such as ethylenediamine, ADTA, DTPA [3] were studed as modifying for difficult compound.Convenient separation from treated water is the other necessity of a promising adsorbent ..In this work,.Bach adsorption studies were carried out to removal of As (III), Pb(II), Cd(II).modified mesoporouswith imiodiacetic acid was prepared and used for removal of heavy metal ions, and good recoveries (PH=8) for As, Pb, Cd are prepared 91,98, 96 respectively .

2.Experimental Mesoporous carbon was synthesized using SBA-15 As template according to the previously reported Procedure [4]. The calcinedSBA-15 sample was further used as template for the synthesis of mesoporous carbon. Sucrose was introduced and polymerized inside SBA-15 with H2SO4 as catalyst according to reference and carbonization in N2 atmosphere by heating to 900 C with a rate of 2 C/min. The template was removed by washing the sorbent (SBA-15) with 1M solution of Na OH in 1:1 EtOH–H2O mixture (twice) at 90 C in order to dissolve the silica template completely. After removal of the silica, the carbon samples were filtered, washed with ethanol and dried at 120 C. 0.1 g of dried CMK-3 powder was treated with 15 ml of HNO3 (1, 2 M solution) for preparation of CMK-COOH.CMK-3–COOH was dispersed in a solution of SOCl2, and then DMF was added and stirred at 70 C for 24 h. The superfluous SOCl2 was removed by being evaporated at 50 C with a rotary evaporation and dried under vacuum. Then the obtainedCMK-3–COCl was mixed with diethyl iminodiacetate in DMF. After stirred under Ar atmosphere at 70 C for 48 h, the solid product was separated, washed with DMF and DDW, and reacted with2.0 mol L−1 HCl (25 mL) under Ar atmosphere at 50 C for 10 h. The prepared CMK-3–IDA were washed with DDW again and dried under vacuum(Fig.1)


Fig.1. Scheme for the synthesis of IDA functionalized CMK-3

3.Results and Discussion FT-IR spectroscopy was performed to characterize the material of CMK-3–IDA. the characteristic peaks at3440 and 1744cm−1 was due to the stretching vibrations of O–Hand C O of –COOH, There were several new spectral bands appeared in the spectrum when CMK–COOH were modified by IDA, and the presence of characteristic peak 1656cm−1 indicated the formation of –NH which demonstrated the IDA has been bonded to CMK-3–COOH successfully .The CMK-3 functionalized by IDA contained more acidic groups such as –COOH, which could adsorb many kinds of metal ions by ion exchange. [Fig. 2]

To assess pH dependence of the adsorption,

solutions pH (3.0–10.0) were selection. The optimum

pH of solutions was 8.0 for Pb (II), As (III) and

Cd (II). The low absorbance of the analytes at low

pH (<3.0) came out of the low retention efficiency

of the packing material possibly because of the

occupation of activity sites by proton, and at high

pH (>8.0), the metal ions maybe hydrolyzed, which

caused the decrease of the absorbance of the

analytes. Under the optimum experimental condition, good recoveries of

heavy metal As, Pb, Cd are obtained in the range of 94-98%

Fig. 2. FT-IR spectra of mag\CMK–COOH (a); mag\CMK–IDA

Reference [1].M. Anbia, S. Amirmahmoodi, ArabianJournal of Chemistry (2011) doi:10.1016/j.arabjc.2011.04.04. [2] .A. Stein, Z. Wang, Adv. Mater., 21 (2009) 265. [3].R. D. Ambashta, M. Sillanpää, Journal of Hazardous Materials180 (2010) 38.

[4] D. Zhao, Q. Huo, J. Feng, B. F. Chmelka, G. D. Stucky, J Am Chem. Soc., 120 (1998) 6024.


Study on humidity sensing properties of K-doped mesoporous silica SBA-15

aS. Mandegarzad ,b*M. Anbia,a. KadkhodazadeS a Research Laboratory of Advanced Materials, Chemistry and Chemical Engineering Research Center of Iran,

P.O. Box 14335-186, Tehran, Iran b Research Laboratory of Nanoporous Materials, Faculty of Chemistry, Iran University of Science and

Technology, Farjam Street, Narmak, Tehran 16846, Iran

*Tel. 982177491204; Fax 982177491204; email: [email protected]

1.Introduction The Increasing demands for evermore sensitive chemical sensors for air-quality detection, environmental monitoring, inflammable-gas inspection, healthcare, industrial production, defense and security, and other applications have led to an upsurge of research devoted to the development of new sensing materials [1–3]. A good humidity sensor should have high sensitivity over a wide range with changes of both humidity.It is known that potassium chloride (KCl) is the best electrolytic materials for humidity sensors. Its operation principle is based on changes of ionic conductivity which occur in a KCl solution. But the shortcoming of this device is that the KCl material is easily soluble even in room environment, so it is difficult to be used at high humidity levels. How to overcome the contamination from dust or oil and how to modify the stability are vital problems [4] for KCl humidity sensors.

In this work, Pure SBA-15 comparing with K-SBA-15 shows improve humidity sensing properties within the relative humidity (RH) range of 11-95. The sample with 12wt. KCl dopant has the best sensingproperties to humidity.

2.Experimental Mesoporous silica SBA-15 was synthesized according to the method reported by Zhao [2] using a triblock copolymer surfactant P123 (EO20PO70EO20) as a template. The detailed procedure is as follows. 2 g P123 was dissolved in a 60ml HCl solution (2 M) at room temperature. Then 4.4 g tetraethyl orthosilicate (TEOS) was added to the reaction container dropwise under stirring at 40 C for 24 h. Subsequently the resultant mixture was aged at 60 C for 24 h without stirring. The product was filtered and washed with distilled water, then dried at 100 C overnight to obtain as-synthesized mesoporous SBA-15. Pure mesoporous SBA-15was obtained by heating the as-synthesized mesoporous SBA-15 for 8 h at 550 C. The surfactant template of the sample was removed during this process. In the following description, we named the as-synthesized meosoporous silica SBA-15 as A-SBA-15, and the pure SBA-15 as P-SBA-15. The main processes are shown in Scheme 1. K-doped A-SBA-15 samples were prepared using the same method as described above. The only difference was that KCl was added together with P123. The resultant samples of KdopedA-SBA-15 were denoted as K-A-SBA-15 (X), where X represents the ratio of KCl to P123 so according to performed experimental X value is equal 12wt.%.

Scheme 1.

3.Results and Discussion Fig. 1 presents the Nitrogen adsorption–desorption isotherms of SBA-15 and K-SBA-15(0.12). As can be seen, K-SBA-15(0.12) shows the same type IV isotherms with H1 hysteresis loops, which are typical for mesoporous materials with two-dimensional hexagonal structures, indicating the mesoporous structure could be retained. The pore size distributions, calculated from the adsorption


isotherms, are shown in the inserted figure in Fig. 1. The centeredpore size decreases from 9.7 nm for SBA-15 to 8 nm for K-SBA-15(0.12).

Fig. 1.Nitrogen adsorption–desorption isotherms of SBA-15 and K-SBA-15(0.12) Fig. 2. Humidity sensitive properties of K-SBA-15 and K-SBA-15(0.12) (insert are the pore size distributions). The isotherm of SBA-15 is shifted byz 300 cm3g−1upward for clarity.

Impedance measurements are performed to describe the as prepared products response to changes in humidity. As shown in Fig. 2, under an electrical field at 100 Hz, SBA-15 shows an obvious change of impedance with respect to the humidity only in ranges larger than 54% RH. The K-SBA-15(0.12) samples show much better linear correlative curve than that of SBA-15. The detection limit for the K-SBA-15(0.12) samples is 11–95% RH, larger than that of SBA-15 (54–95% RH), exposing the presence of KCl directly contributes to the increase of the conductivity and the improvement of the linearity. The response time (as the humidity changes from 11 to 95% RH) is 60 s and the recovery time (as the humidity changes from 95 to 11% RH) is180 s. To test the stability of K-SBA-15(0.12), the sensor was exposed inair for 60 days, followed by measuring impedances at various RH.As shown in Fig. 3, there is acceptable change in the impedances,proving the good stability of K-SBA-15(0.12).

Fig. 3.Stability of K-SBA-15(0.12) measured at 100 Hz.

References

[1] Y. Shimizu, S. Kai, Y. Takao, T. Hyodo, M.Egashira, Sens. Actuators B Chem., 65 (2000) 349–357. [2] G. Li, X.S. Zhao, Ind. Eng. Chem. Res. 45 (2006) 3569–3573. [3] S. Zampolli, I. Elmi, F. Ahmed, M. Passini, G.C. Cardinali, S. Nicoletti, L. Dori, Sens. Actuators B Chem. 101 (2004) 39–46. [4] J. Wang, W.P. Yan, Mater. Chem. Phys. 69 (2001) 288–291.


Clinoptilolite in broiler nutrition

F. .,cM. Afzali .,b ., P. Poorghafour Langeroodia A. Tatar, .a SafariM. H. Moradi d., S. Faryadi e., A. Yousefi-Golverdid., M.T. Shafieef. and A. Farhadi d.

aDept. of Animal Sciences, Gorgan University of Agricultural Sciences and Natural

Resources, Gorgon, Iran b DVM, Faculty Member-A Research Mentor, Research Center of Agriculture and Natural Resources

of Golestan Province, Gorgan, Iran c Islamic Azad University of Sari, Sari, Iran

d Dept. of Animal Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran e Payam Noor University of Hamedan, Hamedan, Iran

f DVM GP, Private Section Veterinarian, 8th Jorjan, Jorjan Blvd., Gorgan, Iran Corresponding author: [email protected]

1.Introduction The main aim of current developmental trends in the nutrition of farm animals is to produce a sufficient quality of animal products and to ensure that produced raw materials will meet strict requirements for food safety. Feeds may contain a number of anti-nutritional substances which may enter food via animals and their products. Suitable procedures are therefore being sought to prevent the contamination of animals with these toxic substances and to control the subsequent penetration of these substances into the food chin. Feed additives also include a group of absorbents which can be used to cope with this problem, for example natural zeolites derived from Clinoptilolites. Clinoptilolites is a mineral derived from hydrated aluminosilicate which contains. Ions such as Ca, K, Na, and Mg, a forms a 3D crystal lattice. This specific structure allows selective absorption of gases. Ions and various low-molecular-weight substances such as mycotoxins. Clinoptilolites are able to selectively exchange their own ions for the ions from the environment [1]. 2.Experimental Animals that were administered feed mixtures containing additives based on Clinoptilolites showed better performance traits, for example, increased weight gain in pigs [4] or increased laying and improved quality of eggs [3]. Apart from the improved performance traits, these additives are also able to absorb ammonia, which is important with respect to the rearing of farm animals as it helps decrease ammonia levels in the stable environment [2]. 3.Results and discussion When administered to broiler chickens at a level of 1% ZeoFeed resulted in an increase in live weight on day 30 of the experimental feeding. This finding was also confirmed in a repeated experiment. The major effect of this product at both levels of age. This proved positive effect on weight gains in chickens during growth is accordance with the finding reported by paaioannou et al. (2004) concerning the effect Clinoptilolite on weight gains in pigs, and with the results of improved performance traits in chickens published by Olver (1997). The results of the


experiment confirmed that the level of the feed additive might be increased with chickens' age. Changeable cations of Zeolites with four-head structure have frail link and they can be easily destroyed or changed through contact with another strong ionic solution. Also Cristal Zeolites are from most effective ion-exchanengers that human being has found it hitherto and its common capacity is special parts of Zeolite which are not available and as a result the effective exchange capacities of that kind of Zeolite decrease for mentioned ion [4]. Also if the dimensions of exchange cations of cross the inlet canals and reach the central hole are very big, there will be the probability to occur the ion-sieving [3]. References 1- M. Boranic, (2000) what a physician should know about zeolites. Lijes. Vjesn, 122, 292-298 2- J. J. Meisinger, A. M. Lefcourt, J. A. Van kessel, V. Wilkerson, (2001): Managing ammonia emissions from dairy cows by amending surry alum or Zeolite or by diet modification. Sci. Word J. 27, 860-865. 3- M. D. Olver, (1997). Effect of feeding of Clinoptilolite (Zeolite) on the performance of three strains of laying hens. Brit. Poultry. Sci. 38: 220-222. 4- D. S. Papioannou, C. S. Kyriakis, C. Alexopoulos, E. D. Tzika, Z. S. Polizopoulou, S. C. Kyriakis. (2004). A field study on the effect of dietary use of a Clinoptilolite-rich tuff, alone or in combination with certain antimicrobials on the health status and performance of weaned, growing and finishing pigs. J. Res. Vet. 76: 19-29.


Study of Catalytic Activity of Nano Structure Modified Cu-Natural Zeolite

for Complete Oxidation of some oxygenated volatile organic compounds (O-VOCs)

aNiaei,A. a,D. SalaribM. Khatamian ,*a N. GhavidelMaroufi

aDepartment of Applied Chemistry and Chemical Engineering, University of Tabriz, Tabriz, Iran bDepartment of Inorganic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran

*Corresponding author: [email protected] 1.Introduction Abatement of pollutant volatile organic compounds (VOCs) has become one of the most important tasks for air pollution control [1-3]. It ishazardous and its emission into the atmosphere has to be controlled according to environmental regulations [4].From the human health viewpoint, this odorant can be harmful even below its normal human perception level. The odor threshold values of this VOC have been prescribed by various authors and agencies such as 5400 ppb, by The United States Environmental Protection Agency (EPA) [5], and 440 ppb prescribed by Nagata and coworkers [6]. The oxidation on catalysts takes place at temperatures which are lower than those required for thermal destruction [7]. This is important in order to improve the economy of the process [8,9].Catalytic Oxidation of ethyl acetate was used as a test reaction to study the catalytic properties and the results of process tested in reactor and analysed by GC. 2.Experimental The Clinoptilolitepowder was treated by HCl solution. The suspension was then washed and dried at 180°C. Cu-Wet impregnation method was used for loading the metal on the support surface. The Clinoptiloliteparticles was added to solution of Copper (II) acetate and stirring was carried out for 12 h at room temperature. Afterward, the resulting emulsion was centrifuged and filtered using deionized water several times. Cu-Clinoptilolitecatalyst was obtained after drying at 110°C andconsequently calcinating in air at 400°C for 4h.Catalyst was placed over a plug of glass wool and placed inside of a U shaped reactor. The reaction was operatedunder steady state in atmospheric pressure.Gas phase products of the reaction weretrapped and analyzed by gas chromatographyusing Shimadzu 2010 GC. 3.Results and Discussion Fig. 2 shows the XRD patterns of catalysts. Fig. 2 indicates XRD pattern of nano Cu-Clinoptilolite. The crystalline structure of clinoptilolite was not significantly changed as the characteristic peaks in the region of 2θ = 9, 22 and 30 was still maintained.

Fig. 3 shows representative SEM micrograph of catalysts. Fig. 3 indicates SEM micrograph of nano Cu-Clinoptilolite. The size of particles is approximately 87 nm.

Fig.2 .XRD patterns ofnano Cu-Clinoptilolite


To study the catalytic activity of catalysts for conversion of VOCs, conversions of ethyl acetate over clinoptilolite and Cu-Clinoptilolite were investigated. To study the catalytic activity of catalysts for conversion of VOCs, conversions of ethyl acetate over clinoptilolite and Cu-Clinoptilolitewere investigated. At first, the conversion of these compounds in absence of catalyst at different temperatures (thermal oxidation) were studied. Afterwards, clinoptilolite and Cu-Clinoptilolitecatalysts were tested. Light-off curves of conversion of ethyl acetate in the absence of catalyst (thermal oxidation), and over clinoptilolite and Cu-Clinoptilolitecatalysts are shown in Fig. 4. In the absence of catalyst, a maximum conversion of 27% resulted for ethyl acetate at 450 °C and at lower temperatures the conversion is very low. Conversion of ethyl acetate over clinoptilolite is more than the conversion of ethyl acetate in the absence of catalysts. This shows that the modification of clinoptilolite with transition metals oxide causes the catalytic activity of catalysts to improve, revealing the catalytic roles of these oxides in the Cu-Clinoptilolite.

References [1] Niaei, A., Salari, D., Hosseini, S.A., Khatamian, M., Jodaei, A., Chinese J. Chem., 27 (2009) 483. [2] Xiaohai Li, Shule Zhang, Yong Jia, Xiaoxiao Liu, Qin Zhong, Volume 21, Issue 1, (2012). 17-24. [3] H. C. Liang, X. Z. Li, J. Hazard. Mater. 162 (2009) 1415. [4] M. Hosseini, T. Barakat, R. Cousin, A. Aboukaïs, B.-L. Su, G. De Weireld, S. Siffert, Applied Catalysis B: Environmental, Volumes 111–112, 12 (2012), 218-224. [5] Jin-Bae Kim, Jong-Il Park, Hong Soo Kim, Yoon Jong Yoo, Journal of Industrial and Engineering Chemistry, Volume 18, Issue 1, 25 January 2012, 425-428. [6] M. Khatamian, M. Irani, J. Iran. Chem. Soc. 6 (2009) 187-194 [7]Alexander Orlov, JacekKlinowski. Chemosphere, Volume 74, Issue 2, January (2009), 344-348. [8]S.S.T. Bastos, S.A.C. Carabineiro, J.J.M. Órfão, M.F.R. Pereira, J.J. Delgado, J.L. Figueiredo, Catalysis Today, Volume 180, Issue 1, 17 (2012), 148-154. [9] B. Silva, H. Figueiredo, O.S.G.P. Soares, M.F.R. Pereira, J.L. Figueiredo, A.E. Lewandowska, M.A. Bañares, I.C. Neves, T. Tavares, Applied Catalysis B: Environmental, In Press, Accepted Manuscript, Available online 10 February 2012.

0

20

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60

80

100

120

150 200 250 300 350 400 450 500

Et A

c C

onve

rsio

n%

Temperature(C)

Thermal oxidation

Fig.4 . Light-off curves of the combustion of Ethyl Acetate on catalysts

Fig.3. SEM imagesofnano Cu-Clinoptilolite


Synthesis, Characterization andLiquid Phase Hydroxylation of Phenolin the presence of Zeolite

encapsulated Oxovanadium(IV) Complexes

Hamid Emadi, MasoudSalavati-Niasari* Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P. O. Box. 87317-51167, Iran

1. Introduction Encapsulation of transition metal complexes in the nanopores of molecular sieves mainly depends on the sizes of both the complex and the pore. The site match of the two is very important to prevent the immobilized catalysts from leaching during reactions. Regular pores or cages are essential requirements for the support. Zeolites are a class of excellent candidates for encapsulation of the homogeneous catalysts.The incorporation of transition metal complexes in porous supports, such as faujasite zeolites, has been known for a long time. This method is typically used to immobilize metal complexes within the supercages of faujasite type zeolites. To avoid the leaching of catalyst during the reaction, a larger transition metal complex than the pore size of the zeolite is encapsulated into the supercage of the zeolite through following three methods: (1) Coordination of the ligands with transition metal atoms previously introduced into the nanopores of zeolites (Flexible Ligand Method; FLM); this approach is based on the principle that the free ligands are flexible enough to pass through the restricting windows and get into the larger cages of the host support. The ligand coordinates to the transition metal atoms previously exchanged onto the host support, zeolite, producing the homogeneous complex catalyst in the zeolite cage. (2) Assembling ligands from smaller species inside the nanopores (Ship-in-Bottle Method; SBM); if the transition metal complex is formed in limited reaction steps, assembly of the ligand from small species within the pores is preferred. Generally, the metal is introduced into nanopores of supports by ion exchange, or by preadsorption of a labile metal complex, and followed by reaction of the smaller molecular fragments with metal ions to form metal complex within the pores.(3) Synthesis of nanoporous support surrounding the performed transition metal complex (Sol-Gel Synthesis Method; SGSM); incorporation of transition metal complexes, by synthesizing the molecular sieve structure around the preformed complexes, could be realized when the metal complexes are able to withstand the synthesis conditions of support and sufficiently soluble in the synthesis medium to enable random distribution of the complexes in the synthesized porous materials. Sol-gel synthesis methods are often used to form silica-based supports around the preformed transition metal complex by polymerization of siloxane precursors. Though the SGSM can successfully encapsulate transition metal complexes inside the porous silica materials, it also brings some disadvantages, such as the poorly defined pore diameters and pore openings of polymerized zeolite compared to the ordered zeolite and the presence of different types of encapsulation sites and space around the catalyst. To avoid the above-mentioned drawbacks, the regular and ordered materials are required for encapsulating the transition metal complexes. In this paper, we report the synthesis and characterization of oxovanadium(IV) complexes of Schiff-base ligands encapsulated within the nanocavities of zeolite-Y (Scheme 1), and used in the oxidation of phenol with H2O2 as oxygen donor.

O

N

CH3

N

CH3

OXX

V

O

Scheme 1.


2. Experimental For Preparation of [VOL]-NaY: a general method; All encapsulated complexes were prepared using a general FLM. Therefore, the preparation of one specific complex, [VOL]-NaY, is outlined here. An amount of OV-NaY and H2L were mixed in a round-bottomed flask. The reaction mixture was heated at 140oC overnight (14 h) in an oil bath with stirring. The melted ligand acted as solvent as well as reactant. The resulting material was taken out and extracted with methanol until the complex was free from unreacted Schiff-base ligand. The solution was filtered and the resulting zeolites, were Soxhlet extracted with N,N'-dimethylformamide.The pale blue-green solid was dried at 120 oC for several hours to constant weight. Oxidation of phenol; Catalytic experiments were carried out in a 50 ml reaction flask fitted with a water condenser. A general procedure was applied for all reactions. In a typical reaction, phenol) and 30% aqueous hydrogen peroxide were mixed in MeCN and the reaction mixture was heated in an oil bath with continuous stirring at 80 oC. The catalyst to be tested (0.025 g) was added to it and the reaction was considered to begin. The reaction products were analyzed using a gas chromatograph after a specific interval of time by withdrawing a small aliquot. The effects of various parameters, such as hydrogen peroxide concentration (moles of H2O2per mole of phenol), phenol concentration (moles of phenol per mole of H2O2), amount of catalyst, temperature, volume of MeCN solvent, etc., have been studied. 3. Results and discussion All the neat oxovanadium(IV) complexes reported are green in colour. Molar conductivities of all the complexes in DMSO solution at 10−3 M concentration show a conductance value in the range 10–15 ohm−1 cm2 mol−1, indicate a nonpolar nature of these complexes. The analytical data indicate that the complexes have the general molecular formula [VOL] and the probable structure of the complexes with Schiff-base ligand.Stirring of oxovanadium(IV) sulfate with NaY in aqueous solutionleads to the formation of oxovanadium(IV) exchangedzeolite; OV(IV)-NaY. Heating of this oxometal exchanged zeolite inexcess of ligands at 140oC for14 hunder stirring allows the insertion of ligands in thenanocavity of the zeolite followed by their complexationwith oxovanadium(IV). The complexation of oxovanadium(IV)species with ligands was accompanied by a colorchange from light blue of exchanged zeolite to paleblue-green. Soxhlet extraction using methanol finallypurified the impure materials. The remaining uncomplexedmetal ions in zeolite were removed byexchanging back with aqueous 0.01MNaCl solution. The chemical compositions confirmed the purity and stoichiometry of the neat and of the zeolite-Ynanopore encapsulated complexes. The chemical analyses of the samples reveal the presence of organic matter with an C/N ratio roughly similar to that for neat complexes. The Si and Al contents in OV-NaY and the zeolite complexes are almost in the same ratio as in the parent zeolite. This indicates little changes in the zeolite framework due to the absence of de-alumination in metal ion exchange. The X-ray powder diffraction patterns of NaY and OV-NaY along with all encapsulated complexes were recorded at 2Ө values between 10 and 70o to study their crystallinity. The XRD patterns of NaY, OV-NaY and [VOL]-NaY. The XRD patterns of vanadium exchanged zeolite and its encapsulated complexes are essentially similar to that of NaY, although a slight change in intensity of the peaks has been noticed. The IR spectra of complexes show a significant change in some important bands from the free Schiff-base ligand. For example the free ligand exhibits a v(C=N) stretch at 1580–1600cm–1. In the complexes, this band shifts to lower frequency and appears at 1575–1590cm–1, indicating the coordination of azomethine nitrogen to the transition metal. The intensity of the peaks of the encapsulated complexes is weak due to the low concentration of the complexes in zeolite. The band due to υ(V=O) could not be located due to the appearance of a strong and broad band of the zeolite framework in the ~1000 cm–1region. All complexes ([VOL] and [VOL]-NaY), exhibit one broad band between 355 and394 nm, which is assigned to a ligand to metal chargetransfer (LMCT) transition. A weak band usuallyappears in the ~560 nm region in oxovanadium(IV)complexes. This band is visible only for [VOL]-NaY as a very weak band. Three spin-allowed transitions in the range 760–770, 550–563 and 470–476cm–1are observed for the present complexes. Thus, IR and UV-VIS data indicate the encapsulation of complexes in the supercages of zeolite-Y.There is a drastic reduction of surface area and pore volume of zeolites on encapsulating the oxovanadium(IV) complexes. Since the zeolite framework structure is not affected by encapsulation as shown by the XRD pattern, the reduction of surface area and pore volume provides direct evidence for the presence of complexes in the cavities. The catalytic oxidation of phenol using [VOL] and [VOL]-NaYas catalysts and H2O2as oxidant was studied. As the hydroxyl group of phenol isortho- and para-directing, the oxidation of phenol isexpected to give two major products, i.e. catechol andhydroquinone. The experimental results confirmed the presence ofthese two major products with a mass balance of>96%. Polymeric material or other products, if any,present as minor constituents


could not be detected bygas chromatography and were neglected. Duringcatalytic oxidation, vanadium complexes react withH2O2 to give oxoperoxo complexes, which ultimatelytransfer oxygen to the substrate. Fig. 1 presents all these data along with percent selectivity for the formation of catechol and hydroquinone. The presence of these two products was also observed with a mass balance of about 96% when phenol was catalysed by nitro complex encapsulated in the nanopore of zeolite-Y using H2O2 as an oxidant. At the end of the reaction, the catalyst was separated by filtration, thoroughly washed with solvent and reused under similar conditions. Although the analysis of the recovered catalysts by AAS showed no reduction in the amount of metal ions, they showed a slightly lower catalytic activity.

Catalyst nitro complex shows the highest conversion. It is interesting to note that even OV-NaY has catalytic activity comparable with that of [VOL]-NaY. However, for OV-Y leaching of the oxovanadium(IV) ion is always possible. Increasing the reaction time from 6 to 24 h does not show any appreciable change in oxidation products.

References

1 P.-P. Knops-Gerrlts, D.D. Vos, F. ThibaultStarzyk and P.A. Jacobs, Nature, 369, 543; (1994);E.J.M. Hensen and J.A.R. van Veen, Catal. Tod. 86, 87; (2003); J. Połtowicz, K. Pamin, E. Tabor, J. Haber, A. Adamski and Z. Sojka, Appl. Catal. A: Gen. 299, 235. (2006). 2 G.S. Mishra and A. Kumar, Catal. Lett. 81, 113; (2002);T. Joseph, D. Srinivas, C.S. Gopinath and S.B. Halligudi, Catal. Lett. 83, 209. (2002) 3 P.A. Awasarkar, S. Gopinathan and C. Gopinathan, Synth. React. Inorg. Met. Org. Chem. 15, 133; (1985); K.S. Siddiqi, N.H. Khan, R.I. Kureshy, S. Tabassum and S.A.A. Zaidi, Indian J. Chem. 26A, 492; (1987); R.H.Groenenman, L.R. MacGillivracy and J.L. Atwood, Inorg. Chem. 38, 208. (1999) 4 P. McMorn and G. Hutchings, J. Chem. Soc. Rev. 33, 108. (2004) 5 I.F.J. Vankelecom and P.A. Jacobs, In Chiral Catalyst Immobilization and Recycling; D.E. De Vos, F. Ivo, J. Vankelecom and P.A. Jacobs, Eds.; Wiley-VCH, 36. 6 M.R. Maurya, M. Kumar, S.J.J. Titinchi, H.S.Abbo and S. Chand, Catal. Lett. 86, 97. (2003); S.Seelan and A.K. Sinha, App. Catal. A: Gen. 238, 201 (2003).

Fig. 1. Bar diagram showing phenol conversion and catechol and hydroquinoneselectivity in acetonitrile for various encapsulated catalysts (Temperature, 80 C;H2O2/phenol molar ratio, 1:1; Time (6 h) Catalyst = 0.025 g)).

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1 2 3 4

Phenol conversion(%)Catechol selectivity(%)Hydroquinone selectivity(%)

1=[VO(haacac)]-NaY2=[VO((CH3)2-haacac)]-NaY3 =[VO(Cl2-haacac)]-NaY 4=[VO((NO2)2-haacac)]-NaY

%


Aqueous colloidal stability evaluated by zeta-potential measurement and resultant TiO2 for superior photovoltaic performance

FargolBijarbooneh a*,Yue Zhao a, Jung Ho Kim a, ZiqiSun a, Victor Malgras a, SeyedHamedAboutalebi a, Yoon-UkHeo b, Masashi Ikegamic and Shi XueDoua

a Institute for Superconducting and Electronic Materials, University of Wollongong, Squires Way, North Wollongong, New South Wales 2500, Australia. Email:[email protected]; Tel: +61-

2- 4298-1413; Fax: +61-2- 4221-5731 b Research Facility Center, Graduate Institute for Ferrous Technology, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784, Republic of Korea.

c Graduate School of Engineering, Toin University of Yokohama, 1614 Kurogane, Aoba, Yokohama, Kanagawa, 225-8503, Japan.

1.Introduction

Controlling the morphological structure of titanium dioxide (TiO2) is crucial for obtaining superior power conversion efficiency for dye-sensitized solar cells. While the sol-gel based process has been developed for this purpose, there has been limited success in resisting the aggregation of nanostructured TiO2, which could act as an obstacle for mass production. Herein, we report a simple approach to improve the efficiency of dye-sensitized solar cells (DSSC) by controlling the degree of aggregation through zeta-potential analysis. We found that different aqueous colloidal conditions, i.e., potential of hydrogen (pH), water/titanium alkoxide (titanium isopropoxide) ratio, and surface charge, obviously led to different particle sizes in the range of 10 to 500 nm. In particular, the particle size was mainly controlled by the pH concentration.

2.Experimental TiO2 was prepared by the conventional sol-gel process.The resulting powder was finally sintered at 500oC for 3 hours.TiO2 paste was prepared by mixing TiO2 powder in DI-water, binder solution, and nitric acid. The solution was heated at 80oC for 5 hours. The resultant TiO2 paste was deposited on a conductive SnO2:F (FTO) glass (Pilkington TEC GlassTM, 7 Ω·sq-1) by the doctor-blade technique. The film was preheated for 30 min at 110oC on a hotplate to remove residual solvent. The film was then heated in a box furnace for 1 hour at 450oC. The resulting layer was ~ 10 µm thick. The annealed TiO2photoanodes were used to prepared the dye sensitized solar cell.


We evaluated the photovoltaic performances of samples with different TiO2 particle sizes prepared by the sol-gel process. In our study, stability of the aqueous colloidal solution was predicted by determining the magnitude of the zeta-potential. Aggregation of TiO2 did not occur in the pH range of 2-3. However, the colloidal solution becomes unstable above pH 4. Eventually, highly acidic conditions led to finer TiO2. It is noteworthy that the specific surface area and the particle size strongly depend on the pH of the aqueous colloidal solution. However, the hydrolysis rate controlled by the water/TIP ratio (R) mainly influences the phase. of 4.24 %, Voc of 0.68 V, Jsc of 8.78 mA·cm-2, and FF of 0.65 were obtained by using the well-dispersed anatase TiO2 with particles 10-20 nm in size.


Fig. 1.(a) Zeta-potential versus pH and (b) colloidal particle size versus zeta-potential.

Fig. 2 (a) Particle size and (b) surface area versus pH.

Fig. 3 SEM images of TiO2nanopowders for R = 4 (a), (c), (e) and R = 30 (b), (d), (f) at pH 2, 7 and 12, respectively.


OptimumConditionsforSynthesis and Characterization ofZeolite Beta

HamidrezaAghabozorga,MasoomehShirzadb, FathollahSalehirada

aN.I.O.C Research Institute of Petroleum Industry,Tehran,Iran

bIslamic Azad University,Teharn North branch, Iran MasoomehShirzad, 09126215375,[email protected]

1. Introduction Zeolite beta is of great potential industrial interest because of its high acidity and peculiar pore system and may be employed as catalyst in a wide variety of hydrocarbon conversion processes includingisomerization, hydration of olefins desulfurization hydrocracking and polymerization. In this work synthesis of zeolite beta was carried out in the presence of an organic template and commercial materials such as silica gel and sodium aluminate.The synthesis parameters such as mole ratios of SiO2/Al2O3 and Na2O/Al2O3, temperature and time of crystallization were studied and optimum conditions for synthesis of this zeolite were obtained. Different techniques such as X-ray diffraction (XRD),infrared spectroscopy (IR) and scanning electron microscopy (SEM) were used to characterize the synthesized samples. 2. Experimental Tetraethylammonium hydroxide (TEAOH) had been used as an organic template.Silica gel powder and an appropriate amount of TEAOH were added to as prepared sodiumaluminate. The mole ratios of the components was as follow:3Na2O:5 (TEA)2O:Al2O3:60 SiO2:1500H2O.The mixture was stirred for 3 hours at room temperature and then heated in a Teflon lined stainless steel autoclave at desired temperature(150-170ºC) for six days. The product was filtered and washed with distilled water. The synthesis parameters such as mole ratios of SiO2/Al2O3 and Na2O/Al2O3, temperature and time of crystallization were studied and optimum conditions for synthesis of this zeolite were obtained. Titanium zeolite beta wasalso synthesized using the mole ratios of the components as follow: 3Na2O:5 (TEA)2O: Al2O3: 40SiO2:1500H2O:0.88 TiO2. Different techniques such as X-ray diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM) were used to characterize the synthesized samples. 3. Results and discussion The XRD patterns of the selected samples are indicated in Fig. 1. The obtained results show that the best range of SiO2/Al2O3mole ratio is from 40 to 60and the temperature of crystallization is 150°C.The presence of TEAOH as a template is important for this reaction.When temperature or time of reaction was increased, the impurity phaseof ZSM-5 was formed.This research indicates that titanium zeolite beta could be obtained by substitution of titanium in the position of silicon andaluminum in thestructure of the zeolite. We can use silica gel and aluminum hydroxide as a source of silicon and aluminum amongof domestic commercial materials.


Fig. 1 The XRD patterns of the selected as prepared samples

References [1] Karin Moller, Bilge Yilmazt, Ulrich Mullert,Chem. Mater, 23(2011)4301-4310 [2] Keith Smith, Zhao Zhenhua and Pilip K.G Hodgson, Journal of Molecular Catalysis, 134(1998)121-128. [3] M. Muller, G. Harvay and R. Prins, Microporous and Mesoporous Materials, 34(2000)135-147. [4]Kadgaonkar, Kasture, Bhange, Microporous and Mesoporous Materials, 101(2007)108-114.


Cobalt-Manganese Containing Nano Pores Santa Barbara Amorphous:Synthesis,Characterization and Catalytic Activity

S.Ali.Monajemi1, VahidMahdavi

Faculty of Science, Department of Chemistry, Arak University, Arak, IRAN, 38156-879 E-mail1: [email protected]

1.Introduction

Nano Pure SBA-15 and Co-Mn incorporated SBA-15 have been prepared by wet

impregnation[1] with three different methods. The best ratio of cobalt to manganese were

obtained 15%Co-2%Mn with high conversion percent(69.3%) in the first method,then two

other synthesis methods have been used in oxidation of ethyl benzene with same metals

loading in liquid phase oxidation of ethyl benzene using TBHP as an oxidant.These results

showed that Nano Manganese increases the catalytic activity.In addition, different methods

cause different activity and conversion in the above reaction. The synthesized samples were

characterized by powder X-ray diffraction, TEM, SEM and N2 adsorption isotherm and

hydrogen temperature-programmed reduction (TPR).

2.Experimental

In this work, we obtain the best ratio of Cobalt to Manganes with high conversion percent

(first method) in oxidation of ethyl benzene then Two other synthesis methods used in same

condition. the effect of calcined temperature and reaction time for best ratio was also studied.

Method 1: After the templates had been completely removed by calcination, 0.85 g SBA-15

was added into water solutions of CoCl2 .6H2O (0.6056 gr for 15%Co/SBA-15 in 100 mL

H2O) and stirred overnight at 35~ 40 After ltered and dried under reduced pressure, the fi

samples was calcined in air at desired temperature for 6 h [2].


Cobalt - Manganese oxides catalysts and other Co-based Nano catalysts were prepared by the

co-impregnation method.Typically 1 gr Co–Mn oxide with various ratio was prepared by the

following procedure: 0.98 gr Co/SBA-15 that prepared ( in the previous section ) and 0.072 gr

Manganese cholorid(MnCl2.4H2O) were dissolved into deionized water. The mixture was

vigorously stirred for 24 h at 35~40 The solid was obtained by ltration and then washed fi

with deionized water for several times[3]. After drying at 100 for 24 h, the solid was

calcined at 530for 6 h. The resulting sample was denoted as 15%Co-2%Mn/SBA-15.

Catalyst

Calcination Time(h)

Calcination Temp( )

Conversion (%)

15%Co-0.5%Mn/SBA-

15

15%Co-1%Mn/SBA-15

15%Co-2%Mn/SBA-15

15%Co-4%Mn/SBA-15

15%Co-6%Mn/SBA-15

15%Co-8%Mn/SBA-15

15%Co-10%Mn/SBA-15

6

6

6

6

6

6

6

530

530

530

530

530

530

530

8.3

24.6

69.3

33.8

17.59

10.24

6.10

Method 2: Just like the first method but manganese cholorid(MnCl2.4H2O) is first,

immobilized on SBA-15 [4].


Method 3: Cobalt and manganese solutions were added dropwisesimultaneously to the

solution of SBA-15 .

References

[1] L. Qingyi, G. Feng, K. Sridhar, E. M. Thomas, J. Am. Chem. Soc., 126, (2004), 8650. [2] D.Y. Zhao, Q.S. Huo, J.L. Feng, B.F. Chmelka, G.D. Stucky, J. Am. Chem. Soc. 120 (1998) 6024–6036. [3] D.Y. Zhao, J.L. Feng, Q.S. Huo, N. Melosh, G.H. Fredrickson, B.F. Chmelka, G.D. Stucky, Science 279 (1998) 548–552. [4] Ling-Xia Zhang, Zi-Le Hua, Xiao-Ping Dong, Lei Li, Hang-Rong Chen, Jian-Lin Shi, J.Mol .Catal A: Chem 268 (2007) 155–162


Adsorption of 2-chloro 4-methyl pyridine by activated kaolin

Saeedeh Hashemian*, Nasim Salehi, Hamideh Bastan Islamic Azad University, Yazd Brunch, Chemistry Department, Yazd, Iran

1. Introduction

4-Methyl pyridine was used in the production of drugs, antidotes and phosphorus-Minute-PAM, is also used pesticides, dyes, rubber additives and synthetic resin production. Pyridine and pyridine derivatives occur in the environment as a result of industrial and agricultural activities. Various physic-chemical and biological treatment techniques are suggested for the treatment of 2-pic-bearing wastewaters [1-3]. Adsorption process is one of the effective methods with the advantages of high treatment efficiency and no harmful by-product to treat water. 2.Experimental The raw kaolin was prepared from mine in Yazd (IRAN). The collected samples were washed repeatedly with deionized water to remove extraneous materials and salts. The kaolin dried in an oven at 500 °C for 24 h. 2-chloro 4-methyl pyridine was purchased from Merck and used without further purification. The standard solutions of 1000 mg L-1 of 2-chloro 4-methyl pyridine was prepared as stock solutions and subsequently whenever necessary, diluted. 3. Results and discussion 1- Characterization of kaolin adsorbent The characterization of kaolin was done. XRD of kaolin is shown on Fig. 1. The XRD pattern of The results of XRD of kaolin indicate the quartz as main phase of clay (2θ=26.6). XRD analysis of kaolin is shown that ouartz, Pyrophyllite, Muscovite and Kaolinite presence in the kaolin phase. Table 1 indicates the kaolin analysis. Fig. 2. Is shown the FT-IR spectrum of kaolin.

Table 1: Characterization of kaolin

Compound Formula %

Quartz, syn SiO2 25.1

Pyrophyllite-2 ITM RG Al2Si4O10(OH)2 35.7

Muscovite 2M1, syn KAl2Si3AlO10(OH)2 25

Kaolinite Al2Si2O5(OH)4 14.3

Fig. 1. Powder XRD for the kaolin

0

200

400

600

800

1000

4 10 20 30 40 50 60 70


Fig. 2. FT-IR spectrum of kaolin

2-Adsorption of 2-chloro 4-methyl pyridine The effect of contact time on the removal 2-chloro 4-methyl pyridine by kaolin for 0.1g kaolin and 30 mL of 2-chloro 4-methyl pyridine 50 mg L-1 is shown in Fig. 3. Adsorption studies were carried out in glass vessels with agitation provided by a shaker. The temperature was controlled at 313 K. The pH was adjusted by addition of HCl or NaOH. The suspensions containing 0.1 g composite varying amount of kaolin were shaken on an orbital shaker at 130 rmp. The result shows the contact time needed for 2-pic to reach equilibrium was 30 min. It can be seen from Fig. 3, the amount of the absorbed 2-chloro 4-methyl pyridine onto kaolin initially, increase with time and, at some point of time, it reaches a constant value beyond which no more is removed from solution. The Fig shows rapid adsorption of 2-chloro 4-methyl pyridine initially up to 30min.

Fig. 3. Effect of contact time of adsorption of 2-chloro 4-methyl pyridine onto activated kaolin References [1]D.H. Lataye, I.M. Mishra, I.D. Mall, J. Environ. Eng. 137(2011) 1048-1057. [2] D. Mohan, K.P. Singh, S. Sinha, D. Gosh, Carbon 43 (2005) 1680-1693. [3]D. Mohan, K.P. Singh, D. Ghosh, Environ. Sci. Technol. 39 (13) (2005) 5076-5086.

0200400600800

10001200

0 20 40 60 80

qe(m

g/g)

T(min)

qe(mg/…


Synthesis of RHO zeolite powder

Seyed foad mousavi a*, Mansoor kazemi moghadam a, Toraj mohammadi a,

*Research Lab for Separation Processes, Faculty of Chemical Engineering, Iran University of Science and Technology, Tehran, Iran.

Tel. +98 (21) 7724 0051; Email: [email protected]

1.Introduction

Zeolites are aluminosilicates with a regular microporous framework. RHO zeolite is one of these zeolites with the following chemical formula:

|(Na+,Cs+)12 (H2O)44| [Al12Si36 O96]-RHO

Its 3D structure is presented in figure 1. It can be used for many applications such as catalyst, ion exchanger, sensor and also animals food additive. Average diameter of RHO zeolite is 3.6 Å.

Figure 1. Representation of RHO zeolite's 3D structure

2.Experimental

For synthesis of this zeolite the following gel formula was used:

1Al2O3 : 10SiO2 : 3Na2O: 0.4 Cs2O : 110 H2O

The used reagents were sodium aluminate (Aldrich chemical Inc.), silica sol (LUDOX TM-50, Aldrich chemical Inc.), 50% CsOH, NaOH (Pellets, Aldrich chemical Inc.) and deionized water. At first 15g deionized water was added to 1.6g NaOH, then 2.8g CsOH was added to the solution and stirred by a magnet on a stirrer. After that, 2.26g aluminate sodium was added to the solution and finally 14.1g silica sol was added slowly during stirring.

After 4 days of stirring, the gel was poured in a PTFE autoclave to heat at 100ºC in an oven. The gel was then kept in the oven for 6 days to synthesize RHO zeolite. At last the crystals were washed by deionized water and heated to be dried. The synthesized dried powder was then characterized using XRD analysis.



Figure 2 shows XRD pattern of the synthesized zeolite powder compares it with its reference pikes. The comparison was performed using a software (XPowder ver. 2010.01.15 PRO). The result confirms 70% crystallinity of the synthesized RHO zeolite powder.

Figure 2. Comparison of the synthesized RHO zeolite powder with its reference

Further investigation is being to undertaken to synthesize better RHO zeolite powders with higher crystallinities.

References

[1] Richard M. Barrer and Miguel A. Rosemblat, Observation on sorption and desorption kinetics of n-hexane in zeolite RHO, Zeolites, Volume 2, Issue 3, July 1982, Pages 231-233.

[2] Robson, Zeolite RHO, US patent 3904738, 1973.


Effectsof natural zeoliteon serum parameters and femur ash content in Japanese quail

Sahab Jenabia, Ahmad Tatara a- Department of Animal Science, Gorgan University of Agricultural Sciences and Natural Resources,

Gorgan, 4681897511, Iran Sahab Jenabi, 09113930273, [email protected]

1.Introduction:

Zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations, have infinite, three dimentsional structures (9). The use of natural zeolite has recently widened as a feed additive in poultry diets. Areas where zeolites have potential use are: a feed additive to improve performance of layers and broilers, to reduce toxic effects of aflatoxin, to assist in manure and litter management (2). The effects of zeolites may be observed due to its high molecular sieve adsorption capacity, effective selection for cations and ion exchange capacity, hydration and dehydration, deodorizing properties and acid resistance. These may play a role in explaining the effectiveness natural zeolite in agriculture (3).Yalcin et al. (1995) examined the effect of different levels of sodium zeolite A on broiler carcass yields and tibia characteristics. Parlat et al. (1999) showed addition 5% zeolite to Japanese quail ration reduced body weight gain significantly during the fourth week. The aim of this study was to evaluate the effects of additional zeolite to Japanese quail ration on serum Ca and P and femur ash factors.

2.Materials and methods: 204 one day old chicks randomly divided into 3 treatments with 4 replicate group per treatment and 17 chicks per replicate. The experiment was performed in a completely randomized design (CRD). Chick diets provided based on NRC (1994) recommendation and formulated with UFFDA1 software. Dietary treatments consisted of a control corn-soybean meal diet and two other treatments contain 1.5 or 3% zeolite for each treatment. Experiment period was 42 days and chicks were kept in a poultry house during this time. All conditions were the same for all replicates. The birds were maintained on a 24- light schedule with free access to water and diets. At the end of period of experiment two birds from each replicate that had a weight near to the mean of that replicate selected and slaughtered after 6 hours withdrawal from feed and water. Blood samples were collected and sent to laboratory to evaluate serum Ca and P. left femur bones separated from the leg to evaluate ash content. The data were analyzed by using of SAS (2003) and the treatments means were compared using Duncan’s multiple range tests (Duncan, 1955) at 5% probability level.

3.RESULTS AND DISCUSSIONS

Table 1 shows the effect of dietary zelite on serum parameters. The results showed no significant change in serum Ca and P between treatments. These results are in agreement with safamehr (2008). From a numerical point of view the most amount of serum Ca observed in zeolite treatments.Sodium ions can be substitutedwith calcium ions in zeolite network, thus calcium ions are more likely to be absorb. Zeolites reduce speed of feed transition in gastrointestinal tract, and so can increase calcium absorption from the feed (3). The amount of serum P in 3% zeolite dietary numerically was less than control treatment.A little amount of zeolite structural aluminum can be separated from the network in the low pH of digestive juices. This aluminum can be bonded with the P in the gastrointestinal tract and reduce its availability by forming insoluble aluminum phosphate (7). 1 - User Feed Formulation Done Again


Dietary containing of 3% zeolite increased femur ash percent significantly (P<0.05) (table 1). This result was in agreement with safaeii et al. (2010) and Yalcin et al. (1995).Because of zeolites ion exchange capacity, they have high ability in absorbing two valent cations such as calcium, in this way, they release this cations slowly in digestive tract and increase blood calcium and more calcium deposition in the bone (9). Researchers showed that zeolites can increase blood Zn and Si in poultries. Although Si is a trace element but it’s necessary for normal bone matrix andprobably bone mineralization. Zn is the component of the carbonic anhydrase enzyme that has a role in calcification of the bone. In addition studies showed Zn role in bone collagen and protein synthesis (3).

Table 1. effect of different levels of zeolite on serum parameters and femur ash. Treatments Calcium (mgL-1) Phosphorous (mgL-1) Femur ash (%)

control 12.53 5.03 54.19 b

1.5% zeolite 13.08 5.22 54.33 b

3% zeolite 13.27 4.57 59.99 a

SEM 0.85 0.16 1.71

Mean with different superscripts in each columns are significantly different (P<0.05).

References: 1-Duncan, D.B. 1955. Multiple range test and multiple F tests. Biometrics. 11:1-42. 2-Eleroglu, H. and Yalcin, H. 2005. Use of natural zeolite_supplemented litter increased broiler production. South

Africa Journal of Animal Science. 35(2): 90-97. 3-Herzig, I., Strakova, E. and Suchy, P. 2008. Long-term application of clinoptilolite via the feed of layers and its

impact on the chemical composition of long bones of pelvic limb (femure and tibiatarsus) and eggshell. Veterinaini Medicina. 53(10):550-554.

4-National Research Council. 1994. Nutrient requirements of poultry, 9th edition national academy press. Washingtone, D.C.

5-Parlat, S.S., Yildiz, A.O., and Ogiuz, H. 1999. Effect of clinoptilolite on performance of Japanese quail (Coturnix coturnix japonica) during experimental aflatoxicosis. British Poultry Science. 40: 495–500.

6-Safaei Ktouli, M., Boldaji, F., Dastar, B., and Hassani, S. 2010. Effect of different levels of Kaolin, Bentonite and Zeolite on broilers performance. Journal of Biological Science. 10(1): 58-62.

7-Safamehr, A. 2008. Effect of clinoptilolite on performance, biochemical parameters and hepatical lesions in broiler chickens during aflatoxosis. Journal of Animal and Veterinary Advances. 7(4):381-388.

8-SAS, 2003. SAS User’s Guide: Statistics. Version 8.2, SAS Institute Inc., Cary, NC. 9-Tatar, A., Boldaji, F., Dastar, B., and Yaghobfar, A. 2008. Effact of perlite and zeolite on serum characteristics,

bone ash, gut pH and performance of broiler chicks . 13th Asian-Australian Animal Science Association Congress. Vietnam. P. 273.

10-Yalcin, S., Bilgili, S.F. and Mcdaniel, G.R. 1995. Sodium zeolite A: influence on broiler carcass yields and tibia characteristics. Applied Poultry Science. 4:61-68.


Investigation on appropriate zeolite membranes for

dehydration

Soheila Ghafarnejhad, Saeed Shirazian, Seyed Nezameddin Ashrafizadeh Research Lab for Advanced Separation Processes, Department of Chemical Engineering, Iran

University of Science and Technology, Narmak, Tehran, Iran

1.Introduction

There is a continuous worldwide interest in zeolite membranes. Zeolite membranes have regular

and molecular-sized pores. They separate molecules based on differences in adsorption and

diffusion properties. Removal of water from chemical compounds is one of the applications of

zeolite membranes. This process is called dehydration. Most of dehydration applications contain

removal of water from alcohols, alkanes, esters, ketones, amines, and other hydrocarbons. The

fundamental aspects of dehydration through zeolite membranes are reviewed and examples of

selectivities and fluxes obtained are presented. Many researchers have work on dehydration by

zeolite membranes via pervaporation and gas separation. Polymeric membranes have been used

for dehydration previously but these membranes may not be suitable for applications involving

high water concentrations or applications containing harsh solvents due to membrane stability

problems and swelling effects. On the other hand, most zeolite membranes have acceptable

mechanical and thermal stability which makes them attractive.

3.Result and discussion

In this review, dehydration by zeolite membranes is discussed. Most of discussed membranes are

hydrophilic ones. Perfect application of dehydration is related to competitive adsorption of water

in hydrophilic membranes and molecular sieve aspects of them. Some hydrophilic membranes

such as NaA, T, SOD, MFI, FAU, and CHA in various applications and their efficiency will be

discussed in this review. But there are some hydrophobic ones which have been used for

dehydration, despite their hydrophobic characters. All silica zeolites are chemically and

hydrothermally more stable than aluminum containing ones and are preferred for membrane

applications including dehydration and will be discussed in this article like DDR zeolite

membrane which removes water by its molecular sieve properties. There are first industrial


applications of zeolite membranes in de-watering of ethanol and i-propanol by LTA membranes.

Some of the topics that are discussed include: Importance of dehydration, water transport

mechanism through zeolite membranes, investigating on various synthesized membranes for

dehydration, industrial dehydration applications of zeolite membranes.


Lead adsorption by a formulated zeolite-Portland cement mixture Hassan Mousavi, SepidehNazariFarsani*

ArdestanCement Company, Iran Email: [email protected]

1.Introduction Zeolite is a naturally occurring crystalline aluminosilicate mineral consisting of a framework of tetrahedral molecules, linked with shared oxygen atoms. Zeolite has a large surface area and high cation exchange capacity, and provides an exchange complex that can adsorb variably-sized ions [1].Since generation of commercial zeolite is expensive, mixtures of zeolite and other less-costly organic and inorganic materials, such as fly ash, portland cement, clays, and polymers, have been formulated for specific pollutants and to reduce material cost [2]. Portland cement is one of the most common materials for solidification and stabilization and has been used as a supplement to zeolite for adsorption purposes [3].

2.Experimental The objective of this research was to investigate the adsorption properties of clinoptilolite zeolite and opsydyan by-product mixed with portland cement (mixture is called ZP) and to compare this mixture to clinoptilolite zeolite and opsydyan for lead removal in wastewater. The ratio of zeolite and opsydyan by-product to portland cement wasselected 85:15.The effect of pH on the adsorption was investigated and optimized. 3.Results and Discussion The effect of pH on the adsorption of Pb2+ by the adsorbents at initial Pb concentration of 500 mgL-1, and samples dose of 0.2 g is shown in (Fig.1,2). It is conceivable that at low pH values, where there is an excess of H30+ ions in solution, a competition exists between the positively charged hydrogen ions and metal ions for the available adsorption sites on the negatively charged adsorbents surface. As the pH increases and the balance between H30+ and OH¯ are more equal, more positively charged metal ions are adsorbed and the amount of adsorbedPb2+onto the zeolite and ZP increased with increasing pH and reached a plateau around pH=4.The adsorption removal of Pb2+wasmaximum at pH=5.0 .Experimentally obtained that the zeolite portlandwas more efficientthan zeolite clinoptilolite and opsydyan for removal oflead from aqueous solutions.


Fig. 1. Effects of pH on adsorption of lead by the (a) Zeolite clinoptilolite(b) ZP in aqueous solution (conditions: 0.2 g adsorbente, 25mL 500 mg L−1 Pb2+solution, contact temperature: 25 C, reaction time: 2 h).

Fig. 1. Effects of pH on adsorption of lead by the (a) Opsydyan (b)Opsydyan-portland in aqueous solution (conditions: 0.2 g adsorbente, 25mL 500 mg L−1 Pb2+solution,contact temperature: 25 C,reaction time: 2 h)

References

[1]Y. Ok,E. Yang , Y. Zhang, S. Kimb, D.Chungd, Heavy metal adsorption by a formulated zeolite-portland cement mixture, J. Hazard. Mater. 147 (2007) 91–96. [2] J.H. Noh, S.M.Koh, Mineralogical characteristics and genetic environment of zeoliticbentonite in Yeongil area, J. Miner. Soc. Korea 17 (2) (2004) 135–145. [3] Th. Perraki, G. Kakali, F. Kontoleon, The effect of natural zeolites on the early hydration of portland cement, MicroporousMesoporous Mater. 61 (2003) 205–212.


Molecular dynamics simulation study of self-diffusion of O2 and CS2 in BEA zeolite

Hossein Mohammadi-Manesh,a,* S.L. Fanib

aDepartment of Chemistry, Yazd University, Yazd, P. O. Box 89195-741, Iran bDepartment of chemistry, Isfahan University of Technology, Isfahan, Iran

*Hossein Mohammadi-Manesh. 0351-8122646, 0351-8210644, [email protected]

1. Introduction

The diffusion of molecules inside the nanometer-scale pores of zeolites controls the performance of zeolites

in many applications of these materials for chemical separations and catalysis. The most straightforward

way is to compute a diffusion coefficient of an adsorbed molecule directly from a molecular dynamics

simulation. In the present study, self-diffusion coefficient and binding energy is investigated for O2 and CS2

gases in BEA zeolite by molecular dynamics simulations. The aim of this study is to understand the effects

of the temperature and kind of guest on the dynamics of the guest diffusion in BEA-type zeolites.

2. Computational and Methodology

The structure of BEA-zeolite consists of interesting 6.5×5.6 and 7.5×5.7 Å channels1. The intermolecular

van der waals potentials between atoms i and j on different molecules are considered to be the sum of

Lennard-Jones (LJ) 12-6 and electrostatic point charge potentials centered on the atoms. To equilibrate the

initial configurations, NVT molecular dynamics simulations with the Nosé-Hoover thermostat-barostat

algorithm were performed on a periodic 333 (a = 12.6Å, c = 26.2Å) replica of the tetragonal with the

DL_POLY molecular dynamics program version 2.18. The simulations have done at a range of

temperatures between 250 and 500 K, at ambient pressure and at a loading 4 of guest molecules per unit

cell and all intermolecular interactions in the simulation box were calculated within a cutoff distance of

Rcutoff = 13.0 Å. A total simulation time of 100 ps is used with an initial temperature scaled equilibration

period of 30 ps.

To obtain the mean-square displacement and diffusion coefficient, NVE simulations were performed for a

minimum total simulation time of 500 ps, starting with configurations equilibrated by the previous NVT

runs. In our model, beta zeolite is assumed to be a rigid. Partial charges are based on local density-

functional theory and semi empirical and in past computations have given satisfactory results with aromatic

molecules in silicalite. The interaction parameters of zeolite used in this work are reported in Table1.

3. Results and discussion

The diffusion coefficient values of O2 and CS2 in BEA zeolite are obtained from the slopes of the mean

square displacement (MSD) versus time plots at different temperatures using the well-known Einstein


relation;

N

iii

trtr

dtd

ND

1

2

)0()(lim61 ; where N is the number of diffusing molecules of type ,

)0(ir and )(tri are the location of the center of mass of molecule i at time zero and t. The diffusion

coefficients for O2 and CS2 at different temperatures are given in table 2. As can be seen from table 2, the

diffusion coefficients increase with temperature and the values are higher for O2. The diffusing molecule

is heavier; its power to move from one site to other sites is less so its diffusion rate is reduced.

The binding energy for the BEA with n guest molecules per unit cell is defined as,

(guests)(BEA)guests)+(BEAbinding nE - E - E =E (1)

The binding energy for O2 and CS2 at different temperatures are given in table 2. The binding energies

decrease with temperature and the values are higher for CS2. at high temperature the movement of

molecules is more than low temperature and their collisions with each other and with the

molecules that want to adsorb will be more, and these collisions avoid adsorbing them.

Table1:Interaction Parameters Used to Represent the Zeolite Framework. q(e) σ ij(Å) ε ij(kJ/mol) atom

2.050 0.677 0.155 Si -1.025 2.708 0.845 O(zeolite) -0.112 3.090 0.369 O(O2) -0.308 3.200 0.424 C 0.154 3.520 1.653 S

Table 2: Diffusion coefficient (10-8 m2.s-1) and the binding energies calculated for O2 and CS2 in BEA

zeolite at loading 4 and at different temperatures.

References

[1] J. M. Newsam, M. M. J. Treacy, W. T. Koetsier and C. B. deGruyter,Proc. Roy. Soc. (London) A420 375–405 (1988). [2] P. Li, F. Handan Tezel, Microporous and Mesoporous Materials 98 (2007) 94-101

T(K) 250 298 330 350 370 400 500

DO2(m2s-1) 2.60 2.76 3.35 3.65 3.67 4.90 5.48

DCS2(m2s-1) 0.21 0.39 0.62 0.84 0.93 1.31 1.86

EO2(kJ mol-1) -5.9 -4.6 -4.3 -4.0 -2.5 -1.9 -0.4

ECS2(kJ mol-1) -29.7 -28.7 -26.6 -25.5 -23.8 -23.2 -21.7


Nano composite HPA /Porous Synthesis by Hybrid Materials and application Of it in preparation of Perimidine

M. Zendehdel* , N. Jafari

Department of Chemistry, Faculty of Science, Arak Uinversity, Arak, Iran

Tel: +988614173401 ext 2314; Fax: +988614173406; E-mail: [email protected]

1. INTRODUCTION In the recent years,solid heteropolyacids (HPA) are known to be active reuse catalysts for a variety of homogeneous acid and heterogeneous acid catalyzed reactions due to their strong Bronsted acidity character compared to homogeneous catalysts such as H2SO4,HCl,AlCl3,etc. For improve the catalytic efficiency of the HPA samples many researchers prefer to support HPA on solid surfaces like carbon, zeoliteY, MCM-411. Perimidines are important chemical classes as a result of their biological activities. 2

The well established method for the preparation of perimidines involves the direct reaction of 1,8-diaminonaphtalene with a carbonyl group which may needs extended reaction times, difficult workup or harsh reaction conditions. 3 This has led to several synthetic methods of perimidines by using different acid catalyst. 4,5 Recently ,using of heterogeneous catalysts, like heteropoly acids and zeolites6,7 in organic synthesis have many advantages such as suitable acidity, low cost, thermal stability, non toxic and environmentally safe. The aim of this paper is the preparation of HPA/NaY and HPA/NaY/AAm HPA/NaY/MCM-41, HPA/NaY/MCM-41/AAm hybrid materials and examines the catalytic behavior the materials towards the synthesis of perimidine. 2. Experimental: Synthesis of Heteropoly acid/NaY composite10 g H3PW12O40 mixed with 16.13 g sodium silicate, 6 mL initiator Then 13.2 mL sodium hydroxide and 5.2 mL deionized water added. The mixture then placed in an autoclave at 100 0C for 24 h. After cooling the reaction mixture to room temperature, filtering,washing with water, and drying in air, the solid product(H3PW12O40/NaY composite) was recovered from themixture. For HPA/NaY/AAm preparation, AAM were added to HPA/NaY. H3PW12O40/NaY/MCM-41 composites 30g H3PW12O40/NaY hybrid added to a fresh MCM-41 gel and mixed with agitation to form a H3PW12O40/NaY/MCM-41 gel, and finally placed in an autoclave at 100°Cfor72h. The result solid filtered, washed with water, calcinated at 540°C for 6h and then characterized. Also For HPA/NaY/MCM-41/AAm preparation AAM were added to HPA/NaY/MCM-41.Preparation of 2-(4-nitrophenyl)-2,3-dihydro-1HperimidineTo a solution of 1,8-naphthalenediamine (0.01 mmol)and 4-nitrobezaldehyde (0.001 mol) in ethanol (20 mL),0.25 g of catalyst added. The reaction mixture refluxed for5 h at 80°C . The used catalyst collected by filtration and then washed with ethanol NaY and MCM-41 prepared in our laboratory as follow by the before method

3.Results and Discussion:

In the case of our synthetic method, XRD, FT-IR and SEM indicate that some of HPA exists on the external surface of HPA/NaY and HPA/NaY/MCM-41 even after washing with water. SEM images of NaY, HPA, and MCM-41 show in Fig.1a-c. Also HPA/NaY nano composite hybrid catalysts are illustrated in Fig.1d. It can be seen that the crystal particle size of HPA/NaYis approximately 2µm. Indeed, particle size of NaY and HPA was500 nm, 200 nm, respectively. In the case of HPA/NaY/MCM-41 nano composite with the crystal size of (2µm) as shown in Fig. 1e. Some rod-like


materials have significant difference in the morphology of some particles, which indicates HPA/NaY covered the external surface of some MCM-41. And also, it can be seen that rod-like MCM-41 is not distinguished and some amorphous phase can be observed.

Fig. 1. SEM for NaY (a) HPA (b), MCM-41 (c), HPA/NaY (d), HPA /NaY/MCM-41 (e)

XRD show HPA may exists in the pore channels on the external surface of NaY and MCM-41.HPA and NaY phases present as a hybrid form. The structure of the zeolite does not collapse upon loading with the strong heteropoly acid. From the FT-IR analysis, it can be concluded that the intensity of characteristic bands become lower, which clearly indicates the existence of HPA and NaY in the pore channels. The preparation of 2-(4-nitrophenyl)-2,3-dihydro-1H-perimidine was carried out to test of these catalysts. Result shows catalytic activity for different samples in order of HPW/NaY>HPW/NaY/MCM-41>HPW/NaY/MCM-41/AAm>HPW/NaY/AAm>NaY>HPW>MCM-41.

References:

1. S. Anandan,S.Yong , W.Cho,M.Yoon, Chem, 195. (2003) 201. 2. I. Kozhevni , V.Russ, Chem.Rev, 56. (1998) 130. 2. G.Caravajal, S.Leyden, D.E.Qunting, G.R.Maciel, G.E.Arel, Chem .Rev, 60. (1988) 1776. 3 T .Barer, W.Cikio, Chem. Rev, 42. (1998) 99. 4. B. Corstanoin, P . Scenzi Metal Oxide Chemistery and Synthesis , 89. (1994) 21. 5. A.Ianos, L.Melo, F.Avendano, A.MontesandJ,L.Brito, catal today, 133. (2008) 20-27. 6. Marme, F.; Coudurier, G.; Védrine, J. C. Microporous and Mesoporous Mater, 22. (1998) 151. 7.M. Zendehdel, A. Mobinikhaledi, H. Alikhani and N. Jafari,Journal of the Chinese Chemical Society,57.( 2010) 683-689.


Effect of supplementation of Zeolite on ruminal fermentation in dairy cows

E. Froutan1, M. Ghahremani2, M. Savari2 and A. Zali2 1- Department of Animal Science, Agriculture faculty, University of Kurdistan, Iran

2- Department of Animal Science, Agriculture faculty, University of Tehran, Iran E. Froutan, +989119729671, [email protected]

1.Introduction

Zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations which have infinite, three dimensional structures (Shariatmadari, 2008; Durali and Tulay, 2011). The wide range of zeolite applications was based on their physicochemical properties (Yolcu et al., 2010; Lithourgidis et al., 2011), in particular, biological characteristics of zeolite such as ion exchange capacity, adsorption and related molecular sieve. Crystalline zeolites have a high attraction for water and large number of positively charged ions, such as K+, NH4, Ca2+, and Mg2+, which can be reversibly bound or released, depending upon the surrounding conditions (Bosi et al., 2002).

Research data reported in the published literature provide evidence of growth promoting effect when zeolite is used as feed additive in animal nutrition (Yazdani and Hajilari, 2009). Research results in dairy cattle suggest that the long-term dietary administration of a natural zeolite, clinoptilolite, has beneficial effects on their health status, performance (Karatzia, 2010; Katsoulos et al., 2005), improve production rates and rumen microbial activity (Sadeghi and Shawrang, 2006, Jonathan et al., 2008).

Due to their ion-exchange property, natural zeolites, when added to acidic or basic aqueous solutions, act as regulatory factors (Filippidis et al., 1996). Although many researchers have attempted to use this property in order to regulate the pH of rumen content for changing the fermentation patterns and for the prevention of subacute ruminal acidosis, their results have been contradictory (Maria et al., 2011).

The high affinity of Zeolite for water and osmotically active cations may facilitate an interaction between fiber and bacteria and the osmotic activity could cause alterations in the rate of liquid flow through the rumen (Johnson et al., 1988).

2.Zeolite effect on ammonia nitrogen produced in rumen

The ion exchange capabiIities of zeolites could possibly influence microbial and animal metabolism through the preferential trapping and release of cations (coollum and galyean, 1983). In addition, supplementing zeolite in dairy diets may improve nitrogen (N) utilization, because zeolite gradually releases excess ammonia (NH3) in the rumen and allows rumen microorganisms to capture the NH3 into microbial protein for assimilation into the animals’ digestive systems (Mumpton, 1999). Mumpton and Fishman, (1977) reported that the zeolite’s ability to act as a reservoir can result in protection of the animal against ammonia overload in the rumen. It is possible that, after the release of ammonia consequent to each meal, zeolite absorbs high levels of NH3 concentration in the rumen and then releases NH3 when its concentration is reduced (Bosi et al., 2002).

Urea can be effectively used by ruminal bacteria to build body protein (that is afterwards digested and used by the cow as a source of amino acids). A diet with a high percentage of soluble nitrogen can release large amount of ammonium in the rumen fluid, especially in the ammonium peak, during the initial post-prandial time (Culfaz and Yagiz., 2004). Zeolite reduces the ammonia concentration in the rumen (Jacobi et al. 1984). Ammonium ions formed by the enzyme degradation of NPN were immediately ion exchanged into the zeolite structure and held there for several hours until released by the regenerative action of Na+ entering the rumen in saliva during the after-feeding fermentation period. The gradual release of NH4+ allowed rumen microorganisms to synthesise cellular proteins continuously available for the animal digestive system (Hemkem et al., 1984).


Zeolyte effect on Rumen pH The dietary administration of clinoptilolite significantly increased the pH of the rumen fluid (Maria et al., 2011). This increase is attributed to the buffer effects of clinoptilolite when added to acidic or basic aqueous solutions (Philipidis et al., 1996). Johnson et al. (1988) reported an increase in ruminal pH when synthetic zeolite was added to the diet of dairy cows. Eng et al. (2003) reported ruminal pH increased by feeding zeolite to steers. Maria et al. (2011) reported Ruminal pH was affected by the addition of clinoptilolite to the concentrate and was significantly higher in group 200 g clinoptilolite (per day) compared to group control (Fig. 1). Zeolyte effect on volatile fatty acid concentrations Despite the contradictory results about ruminal pH, it is well documented that both natural and synthetic zeolites cause changes in rumen fermentation patterns which affect the molar proportions of volatile fatty acids. However, the changes on the proportion of volatile fatty acids are not constant. In some studies it is concluded that zeolites increase the proportion of propionate (collum and galyean, 1983), and in others, decrease the proportion of propionate (Johnson et al., 1988) and valerate, and increase that of acetate (Grabherr et al., 2009). The effects of supplementing zeolite on ruminal VFA composition have been variable among studies. Maria et al. (2001) reported that the molar proportions of propionate and valerate were significantly lower throughout the experiment and at each sampling point in group 200 g of clinoptilolite (per day) compared to control group (P<0.05). The molar proportions of butyrate and iso-fatty acids were not influenced by clinoptilolite (P>0.05) and the molar proportions of the Acetate was increased. Paolo et al. (2002) reported that the inclusion of clinoptilolite in the diet (200g/d) had no effect on rumen concentration of volatile fatty acids (VFA). Molar proportion of acetate, butyrate and minor acids in rumen fluid was not different among treatments. This could mean that clinoptilolite did not adsorb these volatile fatty acids. Johnson et al. (1988) using 2.0% clinoptilolite in the cow diet reported a decrease in propionate concentration with an increase in acetate to propionate ratio. Dschaak et al. (2011) reported that the Clinoptilolite supplementation (1.4% DM) had no significant effect on Ruminal fermentation characteristics of lactating dairy cows (Table 1). The exact mechanism by which clinoptilolite might affect the molar proportion of volatile fatty acids in rumen is currently unknown and needs further investigation.


Table 1. Ruminal fermentation characteristics of lactating dairy cows fed ruminal buffer additives.

References Bosi, P., Creston, D and Casini, L. Production performance of dairy cows after the dietary addition of

clinoptilolite. Ital. J. Anim. Sci 2002. 1, 187-195. Collum, F.T and Galyean, M.L. Effects of Clinoptilolite on Rumen Fermentation, Digestion and Feedlot

Performance in Beef Steers Fed High Concentrate Diets. J Anim Sci 1983. 56, 517-524. Culfaz, M and Yağiz, M. Ion exchange properties of natural clinoptilolite: leadsodium and cadmium-sodium

equilibria. Separation and Purification Technology 2004. 37, 93-105. Dschaak, C.M., Eun, J.S., Young, A.J., Stott, R.D and Peterson, S. Effects of Supplementation of Natural

Zeolite on Intake, Digestion, Ruminal Fermentation, and Lactational Performance of Dairy Cows The Professional Animal Scientist 2010. 26, 647–654.

Durali, D. and Tulay, A. Effects of zeolite (clinoptilolite) on some water and grouth parameters of rainbow trout (oncorhynchus mykiss Walbaum, 1792). Digest Journal of Nanomaterials and Biostructures 2011, 6, 1111-1116.

Eng, K.S., Bectel, R and Hutcheson, D.P. The buffering activity of a potassium clinoptilolite zeolite in steers fed a high concentrate steam flaked grain-corn silage diet. J Dairy Sci 2003. 86, 167, Supplement 1.

Filippidis, A., Godelitsas, A., Charistos, D., Misaelides, P and Kassoli-Fournaraki, A. The chemical behaviour of natural zeolites in aqueous environments: interactions between low-silica zeolites and 1 M

NaCl solutions of different initial pH-values. Appl Clay Sci 1996. 11, 199–209. Grabherr, H., Spolders, M., Furll, M and Flachowsky, G. The effect of several doses of zeolite A on feed intake, energy metabolism and on mineral metabolism in dairy cows around calving. J Anim Physiol

Anim Nutr 2009. 93,221–236. Hemkem, R.W., Harmon, R.J and Mann, L.M. Effect of clinoptilolite on lactating dairy cows fed a diet

containing urea as a source of protein. In: W.G. Pond and F.A. Mumpton (Eds.) Zeo Agricolture, Use of Natural Zeolites in Agricolture and Aquaculture. Westview Press, Boulder, Colorado 1984, pp 171-176.

Jacobi, U., Vrzgula, L., Josef, B and Havassy, I. Study of the effect of zeolite (clinoptilolite) on the dynamics of some parametersof nitrogen metabolism after feeding in the portal and jugular veins and in the rumen fluid of bulls. Veterinarni Medicina 1984. 29, 207-216.

Johnson, M.A., Sweeney, T.F and Muller, L.D. Effects of Feeding Synthetic Zeolite A and Sodium Bicarbonate on Milk Production Nutrient Digestion, and Rate of Digesta Passage in Dairy Cows. J Dairy Sci 1988. 71, 946-953.


Jonathan, C.E., Andrea, P., Iyerusalem, H and Premalathan, J. Effects of dietary Zeolites (bentonite and mordenite) on the performance of juvenile rainbow trout Onchorhynchus myskis. Australian Journal of Basic and Applied Sciences 2008. 2, 961-967.

Karatzia, M.A. Effect of dietary inclusion of clinoptilolite on antibody production by dairy cows vaccinated against Escherichia coli. Livest Sci 2010. 128,149–153.

Katsoulos, P.D., Roubies, N and Panousis, N. Effects of long-term dietary supplementation with clinoptilolite on incidence of parturient paresis and serum concentrations of total calcium, phosphate, magnesium, potassium and sodium in dairy cows. Am J Vet Res 2005. 12,2081–2085.

Lithourgidis, A.S., Dordas, C.A., Damalas, C.A. and Vlachostergios, D.N. Annual intercrops: an alternative pathway for sustainable agriculture. Australian Journal of Crop Science 2011, 5, 396-410.

Maria A. K., Pourliotis, K., Katsoulos, P.D and Harilaos Karatzias. Effects of In-Feed Inclusion of Clinoptilolite on Blood Serum Concentrations of Aluminium and Inorganic Phosphorus and on Ruminal Ph and Volatile Fatty Acid Concentrations in Dairy Cows. Biol Trace Elem Res 2011. 142,159–166.

Mumpton, F.A., and Fishman, P.H. The application of natural zeolites in animal science and aquaculture. J. Anim. Sci 1977. 45, 1188.

Mumpton, F. La Roca Magica: Uses of natural zeolites in agriculture and industry. Proc. Natl. Acad. Sci 1999. USA, 96, 3463.

Paolo, Bosi., Davide, C and Luisa C. Production performance of dairy cows after the dietary addition of clinoptilolite. Ital.J.Anim.Sci 2002. 1, 187-195.

Sadeghi, A and Shawrang, P. The effect of natural zeolite on nutrient digestibility, carcass traits and performance of Holstein steers given a diet containing urea. Animal Sciences 2006. 82: pp 163- 167.

Shariatmadari, F. The application of zeolite in poultry production. World's Poultry Science Journal 2008, 64, 76-84.

Yazdani, A.R. and Hajilari, D. Application of natural zeolite on blood characteristics, physiological reactions and feeding behaviours of finishing Holstein beef steers. Indian Journal of Animal Research 2009. 43, 295-299.

Yolcu, H., Gunes, A., Dasc , M., Turan, M. and Serin, Y. The effects of solid, liquid and combined cattle ımanure applications on yield, quality and mineral contents of common vetch and barley intercropping mixture. Ecology 2010, 19, 71-81.


The effects of zeolites as feed additives on the prevention of farm Ruminants diseases

E. Froutan1, M. Ghahremani2, M. Savari2 and F. Fatehi2

1- Department of Animal Science, Agriculture faculty, University of Kurdistan, Iran 2- Department of Animal Science, Agriculture faculty, University of Tehran, Iran

E. Froutan, +989119729671, [email protected]

1.Introduction

The present review comments on the role of the use of zeolites as feed additives on the prevention of certain farm ruminant diseases. Both natural and synthetic zeolites have been used in animal nutrition mainly to improve performance traits. Zeolites are crystalline hydrated aluminosilicates of alkali and alkaline earth cations; they are characterised by the ability to lose and gain water reversibly, to adsorb molecules of appropriate diameter, to act as molecular sieves and to exchange their constituent cations without a major change in their structure (Mumpton and Fishman, 1977). The exploitation of these properties underlies the use of zeolites in a wide range of industrial and agricultural applications and particularly in animal nutrition (mumptone, 1999). Researches had demonstrated that their use additionally has favorable effects on the prevention certain farm ruminant diseases. Zeolite substances are found in mines throughout the world or may be formed via various manufacturing processes (Douglas et al., 2008). Among a high number of natural zeolites, clinoptilolite is best known (Trckova et al., 2004). Recently, the European Commission has provisionally authorised the use of clinoptilolite of volcanic or sedimentary origin as additive in feedstuffs for farm animals (European Commission Regulation, 2001). Apart from the positive effects on animals' performance, dietary supplementation of zeolites appears to represent an efficacious, complementary, supportive strategy in the prevention of certain diseases and the improvement of animals' health status (Papaioannou et al., 2005). In the medical practice, clinoptilolite is effective as anti-diarrheic drug (Rodriguez-Fluentes et al., 1997), antibacterial and antiviral properties (Grce and Pavelic, 2005). Researches had demonstrated that their use additionally has favorable effects on the prevention and/or treatment of certain farm animal diseases (simona et al., 2010). Inclusion of clinoptilolite in feed during late pregnancy improved the energy status of the animals and significantly reduced the incidence of metabolic disorders such as ketosis (Katsoulos et al., 2006) and periparturient paresis (Katsoulos et al., 2005c).

2.Zeolites effects on the incidence of ketosis

The critical period for the development of ketosis is the first month of lactation because the energy a cows requires for the increased milk production and maintenance of its body tissues significantly exceeds the energy it can obtain from its food intake (Katsoulos et al., 2006). According to Katsoulos et al. (2005), the use of clinoptilolite has been shown to be effective in improving the energy balance at this critical period. The mechanisms by which clinoptilolite may enhance the energy metabolism of dairy cows and so reduce the incidence of ketosis are not clearly understood, but there are two possible explanations which may operate either alone or in combination. The first is that clinoptilolite may increase the production of propionate in the rumen. Many researchers have suggested that the enhancement of propionate production in the rumen prepartum reduces the incidence of ketosis in dairy cattle (Mandebvu et al., 2003; Kokkonen et al., 2004), and the antiketogenic action of propionate has been described by Grummer (1993). Mccollum and Galyean, (1983) observed that when steers were fed on high concentrate diets, the molar proportions of propionate were increased by the addition of 2.5 per cent clinoptilolite in their ration but not by 1.25 per cent. The second possible explanation is that the addition of 2.5 percent clinoptilolite may improve the postruminal digestion of starch. Garcia Lopez et al. (1992) reported that zeolites alter the postruminal pH, which becomes more acceptable for the action of alpha-amylase pancreatic enzyme in the digestion of compounds containing starch. A higher faecal pH, which indicates more complete


digestion of dietary starch and reduced faecal losses of grain have been observed when clinoptilolite was added to the ration of dairy cattle (Hemken et al., 1984). 3.Zeolites effects on the incidence of milk fever

Milk fever is a hypocalcaemic paresis (disorder of nerve and muscle function) at parturition, caused by the sudden and large demand of calcium from blood due to the onset of lactation. Milk fever, more frequent in older cows with high milk yields, is an economically important disease of dairy cows. If left untreated, about 60 to 70% of such cows die. Hypocalcaemia has also some widespread effects on the cow that predispose the cow to other periparturient diseases as mastitis, ketosis, and dystocia, displaced abomasum, and retained placenta (Curtis et al., 1983). Prevention of parturient hypocalcaemia has been the subject of intensive research during the last six decades (Mohebbi and Azadnia, 2011). Most dietary prevention principles of milk fever are directed to the homeostatic regulation of blood calcium and its efficacy, respectively. Low dietary calcium in the prepartum period is seen as one of these preventative dietary regimes (EFSA, 2004). But this method has been almost abandoned because by using common feeds it is almost impossible to keep the Ca intake sufficiently low. More recently, Katsoulos et al. (2005) showed that clinoptilolite was effective in the prevention of milk fever as well. The decrease of availability of feed calcium by adding calcium binding substances may be seen as a further development of the low dietary calcium principle. The crystalline clay mineral zeolite (sodium aluminium silicate) may act as such a calcium binder exchanging its sodium ion with calcium ions and/or other cations (EFSA, 2004). The incidence of milk fever was significantly lower in cows that were receiving a concentrate supplemented with clinoptilolite at the level of 2.5% (5.9%) during the last month of the dry period and the onset of lactation compared to the animals in the control group (38.9%), which were not receiving clinoptilolite, whereas was not significantly different than those that were receiving 1.25% clinoptilolite (17.6%) with the concentrates at the same period (Katsoulos et al., 2006). Zeolites effects on the adsorption of mycotoxins

In recent years, contamination of cereal grain and animal feed with mycotoxins has become a global concern (Dakovic et al., 2007). Mycotoxins are toxic metabolites produced by fungi. According to WHO, about 25% of world’s food is contaminated by mycotoxins (Upadhaya et al., 2010). The most common mycotoxins found in animal feed are aflatoxins, ochratoxins, trichothecenes, fumonisins, zearalenone, and ergot alkaloids (IARC Monographs, 1992). The consumption of these mycotoxin-contaminated feedstuffs by animals leads to adverse effect on animal health and the effects are more serious in monogastric animals depending on the species and the susceptibility to toxins within the species (Upadhaya et al., 2010). One approach to detoxifying mycotoxin contaminated animal feedstuffs is addition of nutritionally inert mineral adsorbents to the diet to decrease the bioavailability of mycotoxins in the gastrointestinal tract (Dakovic et al., 2007). The natural and synthetic zeolites (Oguz et al., 2000b), bentonites (Rosa et al., 2001) and clinoptilolite were preferred because of their high binding capacities against AFs and their reducing effect on AF absorption from the gastrointestinal tract (Ortatatli and Oguz, 2001). Clinoptilolite has high adsorption indexes in vitro, more than 80%, for aflatoxins B1 and G2 agents that produce mycotoxicoses (Papaioannou et al., 2005). Zeolites effects on neonatal calf diarrhea

Neonatal calf diarrhea is the most common disease that affects newborn calves leading to high mortality and high economical losses. Adding clinoptilolite (natural zeolites) in colostrum reduces the incidence of diarrhea syndrome (Simona et al., 2010). The neonatal calves are born with no immunoglobulins in the blood stream and rely on them from colostrum through passive immunity transfer (Davis and Drackley, 1998). Passive immunity is critical to the survival and health of neonatal calves. Low blood immunoglobulin concentrations are directly related to calf morbidity and mortality (Besser and Gay, 1994), aswell as long-termcalf performance (Wittum and Perino, 1995). Improving the transfer of IgG and also reduceing morbidity in calf neonatal period can be obtained by adding clinoptilolite, natural zeolite in colostrum (Fratric et al., 2005). Clinoptilolite added in


colostrum increased the net absorption with 40% of IgG in calves' serum, reducing the number of calves with health problems ( Fratric et al., 2007). Sadeghi and Shawrang, (2008) demonstred that adding 0.5g and 1g/kg body weight per day in colostrum and milk through 45 days reduced fecal score and its severity. These results are caused by retarding effect of clinoptilolite on intestinal passage rate. Their water adsorption property leads to the appearance of drier and more compact feces (Mumpton, 1999). Sadeghi and Shawrang, (2008) reported that adding of 1.0 g clinoptilolite per kg body weight per day to colostrum and milk is appropriate dose for reducing incidence and severity of diarrhea in newborn Holstein calves. Extending the clinoptilolite application over 1.0 g/kg body weight per day to colostrum and milk had adverse effect on passive immunity and diarrhea.The researchers stated that the adverse effect of 1.5 and 2 g clinoptilolite on passive immunity and diarrhea of calves may be related to increase of the abomasal pH and osmotic pressure in the small intestine because of ion-exchange property of clinoptilolite. Inhibiting effect of clinoptilolite on clotting of colostrum and milk proteins (calves on 1.5 and 2 excreted fermented whole milk) resulted in increase of fecal score and diarrhea severity. Simona et al. (2010) reported that Clinioptilolite added in colostrum appeares to reduce the incidence of diarrhea, this could be a result of: alteration of metabolic acidosis through effects on osmotic pressure in the intestinal lumen; or through retention of the enterotoxigenic Escherichia coli thus limiting its attachement to the intestinal cell membrane receptors.

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Davis, C.L and Drackley, J.K. The Development, Nutrition, Management of the Young Calf. Iowa State University Press/ Ames, USA. 1998.

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Fratric, N., Stojic, V., Jankovic, D., Samanc, H and Gvozdic, D. The effect of a clinoptilolit based mineral adsorber on concentrations of immunoglobulin G in the serum of newborn calves fed different amounts of colostrum, Acta Veterinaria 2005, 55, 1, 11-21.

Fratric, N., Stojic, V., Rajcic, S and Radojicic, B. The effect of mineral adsorbent in calf diet colostrum on the levels of serum immunoglobulin G, protein and glucose, Acta Veterinaria 2007, 57, 2-3, 169-180.

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Hemken, R. W., Harmon, R. J. and Mann, L. M. Effect of clinoptilolite on lactating diary cows fed a diet containing urea as a source of protein. In Zeo-Agriculture. Use of Natural Zeolites in Agriculture and Aquaculture. Eds. Westview Press 1984, pp 175-181.

IARC Monographs on the Evaluation of Carcinogenic Risk to Humans. Some Naturally Occurring Substances: Food Items and Constituents, Heterocyclic Aromatic Amines and Mycotoxins. WHO, International Agency for Research on Cancer, 1993, p. 445.

Katsoulos, P.D., Panousis, N., Roubies, N., Christaki, E., Arsenos, G and Karatzias, H. Effects of long-term feeding of a diet supplemented with clinoptilolite to dairy cows on the incidence of ketosis, milk yield, and liver function. Vet. Rec 2006,159, 415–418.

Katsoulos, P.D., Roubies, N., Panousis, N., Arsenos, G., Christaki, E and Karatzias, H.. Effects of long-term dietary supplementation with clinoptilolite on incidence of parturient paresis and serum concentrations of total calcium, phosphate, magnesium, potassium, and sodium in dairy cows. Am. J. Vet.Res 2005c, 66, 2081–2085.

Kokkonen, T., Tesfa, A., Tuori, M. and Syrjala.Qvist, L. Concentrate feeding strategy of dairy cows during transition period. Livestock Production Science 2004, 86, 239-251.

Mandebvu, P., Ballard, C.S., Sniffen, C. J., Tsang, D. S., Valdes, F., Miyoshi, S. and Schatter, L. Effect of feeding energy supplement prepartum and postpartum on milk yield and composition, and incidence of ketosis in dairy cows. Animal Feed Science and Technology 2003, 105, 81-93.

Mohebbi-Fani, M. and P. Azadnia. The effect of subcutaneous injection of calcium borogluconate on serum levels of calcium, phosphorus and magnesium in newly calved cows. Comp Clin Pathol 2011.DOI 10.1007/s00580-011-1342-0.

Mumpton, F. A and Fishman, P. H. The application of natural zeolites in animal science and aquaculture. Journal of Animal Science 1977, 45, 1188- 1203.

Mumpton, F. A, Proc. Natl. Acad. Sci 1999 USA. 96, 3463. Ogguz, H., Kurtoglu, V. and Coskun, B. Preventive efficacy of clinoptilolite in broilers during chronic

aflatoxin (50 and 100 ppb) exposure. Research in Veterinary Science 2000b, 69, 197–201. Ortatatli, M. and Ogguz, H. Ameliorative effects of dietary clinoptilolite on pathological changes in

broiler chickens during aflatoxicosis. Research in Veterinary Science 2001. 71, 59–66. Papaioannou, D., Katsoulos, P.D and Karatzias, H. The role of natural and synthetic zeolites as feed

additives on the prevention and/or the treatament of certain farm animal diseases: a review, Microporous and mesoporous materials, 2005, 84, 161-170.

Rodriguez-Fluentes, G., Barrios, M.A., Iraizoz, A., Perdomo, I and Cedre, B. Enterex-anti-diarrheic drug based on purified natural clinoptilolite. Zeolites 1997,19, 441–448.

Rosa, C. A., Miazzo, R., Magnili, C., Salvano, M., Chiac, S. M., Ferrero, S., Saenz, M., Carvalho, E. C and Dalcero, A. Evaluation of the efficacy of bentonite from the south of Argentina to ameliorate the toxic effects of AF in broilers. Poultry Science 2001, 80, 139–144.

Sadeghi, A and Shawrang, P. Effects of natural zeolite clinoptilolite on passive immunity and diarrhea in newborn calves, Livestock Science 2008. 113, 2-3, 307-310.

Mumpton, F.A., La roca magica: Uses of natural zeolites in agriculture and industry, Proc. Natl. Acad. Sci., 1999, 96, 3463-3470.

Simona, Z., Camelia, T., Samanc., Danijela. Kirovski, H., Cernescu, H and Mircu, C., Clinical observations in calves fed colostrums supplemented With clinoptilolite Lucr. St. Med. Vet 2010, XLlll (2), 64-69.

Trckova, M., Matlova, L., Dvorska, L and Palvic, I. Kaolin, bentonite, and zeolites as feed supplementsfor animals: health advantages and risks. Vetrinarni Medicina 2004, 49, 389-399.

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Wittum, T.E and Perino, L.J. Passive immunity at postpartum hour 24 and long-term health and performance of calves. Am. J. Vet. Res 1995. 56, 1149–1154.


The effect of feeding zeolite on feed intake and performance of animal

M. Savari1, F. Fatehi1, E. Foroutan2 and M. Ghahremani1

1-Department of animal science, Agriculture Faculty, university of Tehran, Iran

2- Department of Animal Science, Agriculture faculty, University of Kurdistan, Iran

M. Savari, +989138172410, [email protected]

1.Introduction Use of silicate minerals in animal nutrition has recently increased, mainly due to their some position effects on animal performance and health. Clinoptilolite is used in a wide range of industrial and agricultural applications, particularly in animal nutrition. Dietary use of zeolites has been shown to improve weight gain rates in growing lambs (14), fattening pigs (13, 10, 1) and broilers (11), to enhance the reproductive performance of sows (2, 4) and to lead to a better feed efficiency and egg productivity in laying hens (8). In this review some of the studies on application of zeolite in animal nutrition described. 2.Animal Health Katsoulos et al. reported that cow fed with ration containing 2.5% clinoptilolite had significantly fewer cases of clinical ketosis during the first week after calving and a higher milk yield. Thilsing-Hansen and Jorgensen (2001) suggested the addition of synthetic zeolite A to the daily ration during the last month of pregnancy prevented parturient paresis as well as subclinical hypocalcemia in Jersey cows. The bene t of clinoptilolite addition to ration on health and fiperformance of weaned, growing, and nishing pigs werefi suggested by Papaioannou et al. (3). Feed intake and animal performance Higher dry matter (DM) intake was reported in beef and dairy cattle consuming zeolites, although growth response was not consistent (5). Sweeney (1980) demonstrated improved nitrogen, organic matter, and acid-detergent bre digestibility when ve clinoptilolites were fi fiadded to a high solubility protein diet of growing steers and heifers (12). Bartko et al. suggested that addition of clinoptilolite at a rate of 0.15 g/kg of live weight per day for 3 months in sheep had no effect on red blood cells (RBC) number. In a study by Christaki et al., The supplementation of 2% NZ( natural zeolite) in the broiler diet resulted in an improvement of the feed conversion ratio and an increase of body weight, carcass yield as well as linoleic


and a-linolenic acid content, without any adverse effect on the other measured parameters. The addition of 4% natural zeolite resulted in a significantly higher feed conversion ratio. In the following tables the effect of feeding zeolite on food intake and performance of animal is presented.

Table 1 Dry-matter intake, daily gain and food: gain ratio of Mehraban lambs as influenced by the dietary level of zeolite (12).

Table 2 Mean ± SE of Total Performance between Trial Groups (9)

However, some researchers have not observed any response relating to the performance of growing and fattening pigs (Pearson et al., 1985), while a reduction in the daily weight gain of growing pigs fed zeolite has also been reported (Poulsen and Oksbjerg, 1995). These contradictory results could be attributed to factors such as the species, the chemical and structural properties of the zeolite used its purity and physicochemical properties, as well as the supplemental level used in the diets (Mumpton and Fishman, 1977; Pond and Yen, 1982; Pond et al., 1988). Furthermore, the dietary conditions under which consistent positive responses to zeolite administration are expected, should also be considered (Poulsen and Oksbjerg, 1995), along with the health status of the treated animals ( 3).


Mode of action The ion-exchange properties of zeolite could affect microbial and animal metabolism through the selective trapping and releasing of cations. The chemical and physical properties of zeolites have been reviewed by Mumpton and Fishman (1977) and Peterson (1980). It has been indicated that zeolites are capable of sequestrating and subsequently releasing proportionately 0·15 of the ammonium ions (NH+4) present in the inoculum and rumen contents (6) although Sweeney et al. (1980) observed no effect of a synthetic zeolite on rumen ammonia (NH3) concentrations. Peterson (1980) suggested a buffering property for zeolite in an acidic environment. Ames (1960) demonstrated high selectivity of zeolite for NH+4(7).

References

1) A. Yannakopoulos, A. Tserveni-gousi, A. Kassoli-fournaraki, A. Tsirambides, K. Michailidis, A.

Filippidis and U. Lutat. Effects of dietary clinoptilolite-rich tuff on the performance of growing nishing pigs. In: C. Coela and F.A. Mumpton (Eds.), Natural Zeolites for the Third Millenium. De fi

Frede Editore, Napoli, Italy, (2000). pp. 471–481. 2) B.V. Cheshmedzhiev, A. Angelov, N. Nestorov, A. Krstev S. Bakalivanov and R. Cheshmedzhieva.

Effect of zeolite in the feeding of pregnant and nursing sows and sucking piglets. Zhivotnov dni Nauki 22, (1985) 40–46 (abstract).

3) D.S. Papaioannou, C.S. Kyriakis, C. Alexopoulos, E.D. Tzika, Z.S. Polizopoulou and S.C. Kyriakis. A eld study on the efi ffect of the dietary use of a clinoptilolite-rich tuff, alone or in combination with certain antimicrobials, on the health status and performance of weaned, growing and nishing pigs. fiResearch in Veterinary Science 76 (2004) 19–29.

4) D.S. Papaioannou, S.C. Kyriakis, A. Papasteriadis, N. Roumbies, A. Yannakopoulos and C. Alexopoulos. A eld study on the efi ffect of in-feed inclusion of a natural zeolite (clinoptilolite) on health status and performance of sows/gilts and their litters. Research in Veterinary Science 72, (2002) 51–59.

5) F.A. Mumpton and P.H. Fishman. The application of natural zeolites in animal science and aquaculture. Journal of Animal Science 45, (1977) 1188–1203.

6) J. L. White and A. J. Ohlrogge. Ion exchange materials to increase consumption of nonprotein nitrogen in ruminants. Canadian patent 939186, 2 January (1974).

7) L. L. Ames. The cation sieve properties of clinoptilolite. American Mineralogy. 45: 689. (1960). 8) M.A. Elliot and H.M. Edwards Jr. Comparison of the effects of synthetic and natural zeolite on

laying hen and broiler chicken performance. Poultry Science 70, (1991) 2115–2130. 9) M. A. Norouzian, R. Valizadeh, A. A. Khadem, A. Afzalzadeh and A. Nabipour. The Effects of

Feeding Clinoptilolite on Hematology, Performance, and Health of Newborn Lambs. Biol Trace Elem Res, 137 (2010) 168–176.

10) M.T. Coffey and D.W. Pilkington. Effect of feeding Zeolite-A on the performance and carcass quality of swine. Journal of Animal Science 67 (Supplement 2), 36 (1989) (abstract).


11) R. Fethiere, R.D. Miles and R.H. Harms. The utilization of sodium in sodium zeolite A by broilers. Poultry Science 73, (1994) 118–121.

12) R. Forouzani, E. Rowghani and M. J. Zamiri. The effect of zeolite on digestibility and feedlot performance of Mehraban male lambs given a diet containing urea-treated maize silage. Animal Science, 78 (2004), 179-184.

13) W.G. Pond, J.T., Yen and V.H. Varel. Response of growing swine to dietary copper and clinoptilolite supplementation. Nutrition Reports International 37, (1988) 797–803.

14) W.G. Pond, S.M. Laurent and H.D. Orloff. Effect of dietary clinoptilolite or zeolite Na-A on body weight gain and feed utilization of growing lambs fed urea or intact protein as a nitrogen supplement. Zeolites 4, (1984) 127–132.


Zeolite as a toxin-binder in animal nutrition

M. Savari1, M. Ghahremani1, E. Froutan2 and F. Fatehi1

1-Department of animal science, Agriculture Faculty, university of Tehran, Iran

2- Department of Animal Science, Agriculture faculty, University of Kurdistan, Iran

M. Savari, +989138172410, [email protected]

1.Introduction

The contamination of feedstuffs and animal feeds by molds is still a world-wide problem and unavoidable, even though a considerable number of field and preservation studies have been done. Mycotoxins are often found in ingredients and feeds as secondary metabolite produced by molds during their life span (12). Clay minerals are naturally derived substances that have been used succesfully in adsorption of mycotoxin to prevent health problems in cattle, pigs and poultry due to feeding of contaminated feedstufs (5). One of the most important applications is using of them as adsorbent of toxin in animal and poultry nutrition. It is because of the large surface area due to the multilayered structure and the positive charge between the layers that many toxins can be trapped by clay minerals (7).

2.Adsorption of mycotoxins

Clinoptilolite, a natural zeolite, has high adsorption indexes in vitro, more than 80%, for a atoxinsBfl 1(2, 10) and G2(2) and the adsorption process begins with a fast reaction whereby most of the toxin is adsorbed within the rst few minutes fi (2).Most studies related to the alleviation of mycotoxicosis by the use of adsorbents are focused on aluminosilicates, mainly zeolites and hydrated sodium calcium aluminosilicates(3). They effectively minimize adverse effects of a atoxins on feed intake, performfl ance and nutrient conversion (13) and reduce mycotoxinconcentration in the livers of affected animals (8). A lower concentration (15 g/kg) of zeolite in the diet seems more effective than a higher concentration (25 g/kg) as it was described by Oguz and Kurtoglu(11). An in vitro study, by N.Q. Thieu and H. Pettersson, using single concentration and isotherm adsorption was carried out to evaluate the capacity of zeolite to


adsorb aflatoxin B1 (AFB1) in simulated gastrointestinal fluids (SGFs), The results of single concentration adsorption showed that, More than 70% AFB1 was adsorbed by zeolite in SGFpH3, but only 20% in SIFpH7(12). An in vitro study, by Dwyer et al., (1997) showed that adsorption capacity of mycotoxins by Clinoptilolite is 0.08 (mg/g)(3). In vivo adsorption of mycotoxins by zeolites is summarized in the below table (6).

Table 1 In vivo adsorption of mycotoxins by different Type of zeolite.

Type ofzeolite Concentration

(%)

Animal Mycotoxin Effects observed Reference

Clinoptilolite 0.5 Weaned

piglets

afl Growth inhibitory

effects were

prevented

Schell et al., 1993

Clinoptilolite 1.0 Broilers Cpa No signi cant effectfi Dwyer et al., 1997

Clinoptilote 5.0 quail

chicks

afl growth inhibitory

effects diminished

Parlat et al., 1999

Zeolite NaA 1 Broilers Protection against

growth inhibitory

effects

Miazzo et al., 2000

Clinoptilolite 2 Laying

hens

afl Signi cant decrease fi

in liver mycotoxin

concentration

Rizzi et al., 2003

Mode of action

During the last decade, utilization of zeolite as mycotoxin-binding adsorbents has been a topic of

considerable interest and many published research data indicate their potential efficacy against

different types of mycotoxins either as a primary material or after speci c modi cations related fi fi

to their surface properties. These clays have been shown to have the ability to adsorb aflatoxins

in in vitro studies and to diminish the adverse effects of aflatoxins in in vivo studies. Molecular

sizes of a atoxins range from 5.18 A (Bfl ˚ 1 and B2) to 6.50 A (G˚ 1 and G2) and only zeolites with

entry channels wide enough to permit the diffusion of a atoxin molecules to the intra crystalline fl


structure are capable of demonstrating a clear sequestering effect. Phillips et al.(1990a)

interpreted the binding mechanism as the formation of a complex by the b-carbonyl systemof the

a atoxin with ‘uncoordinated edge site’aluminiumions.fl In conclusion, a broad base of scienti c fi

data veri esthat the proliferation of zeofi lites dietary use will contribute to the improvement of

animals health status, additionally implying a potential improvement in nalfi meat and dairy

products quality(6).In the case of phyllosilicates, the results of in vitro mycotoxin–clay

interaction tests suggest the existence of areas of heterogenous adsorption affinities onto surface,

the presence of different adsorption mechanisms or both (4). Nevertheless, the formation of

strong bonds by chemisorption and the interaction of b-carbonyl group of a atoxin Bfl 1 with the

uncoordinated edge site aluminum ions in these adsorbents have been suggested as the binding

mechanism which interprets their well-established high affinity for a atoxin Bfl 1(1). Although the

exact binding mechanisms of zeolites on a atoxins have not been determined the possibility to fl

act through similar with phyllosilicates mechanism cannot be precluded and should be

investigated. Remarkable conclusions related to zeolites efficacy against zearalenonetoxicosis

have also been drawn by in vivo studies. Feeding zearalenone to ratsdemonstrated that the

dietary use of a synthetic anion exchange zeolite could alter the faecal and urinary excretory

patterns of zearalenone due to the elimination of its intestinal absorption (14).The AF

sequestering capacity of smectite clay is mediated through electric elementary charges between

the beta-carbonil portion of the a atoxin molefl cule and sites containing

aluminium ions (9).

References

1) A.B. Sarr, B.A. Clement and T.D. Phillips, Toxicologist 10 (1990)163. 2) A. Dacovic, M. Tomacevic-Canovic, V. Dondur, A. Vujakovic, P. Radosevic and J. Serb.

Chem. Soc. 65 (2000) 715. 3) A. Huwig, S. Freimund, O. Kappeli and H. Dutler. Mycotoxindetoxication of animal feed by

different adsorbents. Toxicology Letters 122 (2001) 179–188. 4) A.J. Ramos, E. Hernandez, J.M. Pla -Del na, M. Merino andfi Int. J. Pharmaceut.128 (1996)

129. 5) D.E. Diaz, W.M. Hagler Jr., B.A. Hopkins and L.W. Whitlow. Aflatoxin binders I: In vitro

binding assay for aflatoxin B1 by several potential sequestering agents. Mycopathologia 156, (2003). 223–226.


6) D. Papaioannou, P.D. Katsoulos, N. Panousis and H. Karatzias. The role of natural and synthetic zeolites as feed additives on the prevention and/or the treatment of certain farm animal diseases: A review. Microporous and Mesoporous Materials 84 (2005) 161–170.

7) H. Spieker. Efficacy of clay minerals and activated charcoal to bind endotoxins in rumen fluid. (2009).

8) L. Rizzi, M. Simioli, P. Rocanda and A. Zaghini, J. Food Protect. 66 (2003) 860. 9) M. Moschini, A. Gallo, G. Piva and F. Masoero. The effects of rumen uid on the in vitfl ro

a atoxinbinding capacity of different sequestering agents and in vivo release of the flsequestered toxin. Animal Feed Science and Technology147 (2008) 292–309.

10) M. Tomacevic-Canovic, A. Dacovic, V. Markovic, D. Stojcic and J. Serb. Chem. Soc. 66 (2001) 555.

11) M. Trckova, L. Matlova, L. Dvorska and I. Pavlik. Kaolin, bentonite, and zeolites as feed supplements for animals: health advantages and risks. Vet. Med. Czech, 49, 2004 (10): 389–399

12) N.Q. Thieu and H. Pettersson. In vitro evaluation of the capacity of zeolite and bentonite to adsorb aflatoxin B1 in simulated gastrointestinal fluids. Mycotoxin Research Vol. 24, No. 3 (2008), 124-129.

13) S.S. Parlat, A.O. Yildiz and H. Oguz. Effect of clinoptilolite on performance of Japanese quail (Coturnixcoturnix japonica) during experimental a atoxicosis. Br. Poult. Sci.40, fl(1999) 495–500.

14) T.K. Smith, Can. J. Physiol. Pharmacol. 58 (1980) 1251.


The effect of physical size of clinoptilolite(natural zeolite) on growth indices of young broilers

BahmanParizadianKavana, Mahmoud Shams Shargha, SaeedHassania and yousefMostafalob

aFaculty of Animal Science, Gorgan University of Agricultural Sciences and Natural Resources, Iran bDepartment of Animal Science, Gonbad University, Iran

Corresponding author,BahmanParizadianKavan,Postal code: 0098-47819- 33839, Tel: 0098- 09118231039, Fax: 0098- 01714440093, Email: [email protected]

1. Introduction Zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations which have infinite, three dimensional structures. Among many properties attributed to zeolites, two most characteristics that relates to their effectiveness in animal nutrition are their ability to lose and gain water reversibly and being capable of exchanging selectively a variety of cations in their structure without much major changes of structure. However the effect of zeolites on feed intake, weight gainand growth rate are in dispute. While some of the experiments report beneficial effect due to inclusion of zeolite in the diet of birds, others show no changes and yet there are results that indicate the negative effects. The discrepancies between studies may result from level of usage, type of zeolite (natural or synthetic) and even within natural ones, the amount of impurities, interspecies differences, age, sex, feeding program, and the managerial or environmental conditions of the animals. On the other hand there has been evidence that zeolites has beneficial effect on feed efficiency ratio, water consumption, nutrient utilization, manure and litter condition and more importantly on aflatoxicosis.Studies on the effect of zeolite particle size on broilers performance are spare. The purpose of this study was, therefore, to evaluate the effect of zeolite particle size and level on growth indices of young broilers. 2. Experimental This experiment was carried out using 448broilers in a completely randomized design with two levels of clinoptilolite(1.5 % and 3 %) and three sizes of clinoptilolite(mash form, 0.4- 0.8 mm and 1- 2 mm) by factorial arrangement. Four replicates with 16broilers were allocated in each experimental treatment and birds were reared from7-21 days. Each cage was equipped with bell-drinker and a feeder. The experimental diets were formulated to meet minimum nutrient requirements of broilers, as established by the National Research Council (NRC, 1994). Experimental diets (in mash form) and water were provided ad libitum. House temperature was maintained at 330C in the first week and reduced 20C weekly thereafter. A continuous lighting program was provided during the experiment. The growth performance of broilers was evaluated by recording body weight gain (BWG), feed intake, and feed conversion ratio (FCR). Individual live body weight of broilers was recorded at the beginning of the experiment and on a weekly basis thereafter. Feed intake for each cage was recorded weekly. Feed conversion ratio was calculated weekly as the amount of feed consumed per unit of body weight gain. The data obtained from the experiment were analyzed using GLM procedure of SAS. Significant differences among treatment means were evaluated using Duncan, s multiple range test. 3.Results and discussion Table 1 shows the effects of particle size and levels of clinoptilolite on body weight gain of broilers. The levels of clinoptiloliteaffected BWG in periods of 7-14, 14-21 and 7-21 days, so that the broilers were fed with clinoptilolite (1.5 %) had a higher (P<0.05) BWG than control group that did not received clinoptilolite. Particle size of clinoptilolitehad no significant effect on the BWG of the broilers. There was no interaction between particle size and levels of clinoptilolitein terms of body weight gain (P>0.05). The using of various levels and particle sizes of clinoptilolitehad no effect on feed intake (P>0.05). There was no interaction between particle


size and levels of clinoptilolite in terms of feed intake (P>0.05). But, clinoptilolite had significant effect on feed conversion ratio during 7-14, 14-21 and 7-21 days of age. Broilers were fed with clinoptilolite (1.5 %) had lower FCR compared other groups. The effects of zeolite on body weight gain and feed efficiency could be due to a reduction in the rate of food passage in the gut that increase digestive enzymes activity and therefore, the nutrients such as fats, proteins and carbohydrates used more. Furthermore, zeolites have been shown to improve the AME, AMEn and true protein digestion ratio, the number, size and shape of intestinal villi, or on metabolic organs such as the liver, kidney and pancreas. Table 1. Effect of clinoptilolite on young broilers performance

Main effects

BWG (g) FI (g) FCR

7-14 days

14-21 days

7-21 days

7-14 days

14-21 days

7-21 days

7-14 days

14-21 days

7-21 days

Control 233.50b 341.00b 574.50b 433.96 731.88 1165.85 1.85a 2.14a 2.02a

Level 1.5% 289.00a 390.83a 679.83a 435.78 749.21 1184.99 1.49b 1.91b 1.73b

3% 275.50a 373.83ab 649.33a 447.53 723.81 1171.35 1.63ab 1.93b 1.80b

Size (mm) <0.25 291.75 387.50 679.25 450.16 737.54 1187.72 1.53 1.90 1.74

0.4- 0.8 282.25 382.00 664.25 438.60 750.19 1188.80 1.54 1.96 1.78 1- 2 272.75 377.50 650.25 436.20 721.79 1158.00 1.61 1.90 1.77

a, b Mean values in the same column with different superscript letters were significantly different (P<0.05).

References Gezen, S.S., Eren, M., Balci, F., Deniz, G., Bincik, H., and Bozan, B. The effect of clinoptilolite in low calcium diets on performance and eggshell quality parameters of aged hens. Asian-Australasian Journal of Animal Science.Vol22. 2009.76-83. Mot, M., Colibar, O., Matiuti, M., and Darlea, A. Natural zeolite: additive to the broiler diet. Yugoslav Poultry Science. Vol3. 1998. 19-21. Petunkin, N. 1991. Influence of zeolites on animal digestion. In: occurrence, properties and utilization of natural zeolite, eds. Fuentes, G.R and Gonzalez, J.A., p. 280. Havana, Cuba. Shariatmadari, F. The application of zeolite in poultry production. World , s Poultry Science Journal. Vol64. 2008.76-84.


Synthesis and Characterization of Co-ZSM-5 and Fe-ZSM-5 Nanozeoliteand Their Applications in Adsorption of Rhodamine B Dye

SeyedKarimHassaniNejad–Darzia,*, AbdolraoufSamadi–Maybodiband MehdiGhobakhluob

a Faculty of Basic Science, BabolNoshirvani University of Technology, Babol, 47148-71167, Iran, bFaculty of Chemistry, University of Mazandaran, Babolsar, 47416-95447, Iran.

*Corresponding author. 09112137102, +98(111)3234203,[email protected]

1.Introduction

Many industries such as textile and printing use dyes and pigments and thus produce highly colored waste effluents. Disposal of these wastes into water causes environmental problems [1]. Various treatment processes such as physical separation, chemical oxidation and biological degradation have been widely investigated to remove dyes from wastewater [2]. Activated carbon has been the most widely used adsorbent; it suffers drawbacks of higher cost in production and regeneration [3]. Synthetic and natural zeolites are important alternatives as adsorbents due to their high ion-exchange and adsorption capacities as well as thermal and mechanical stabilities [4]. Modified nanozeolite with cobalt and iron has some ion exchangeable cations such as Co2+ and Fe2+ in channels. Such cations give a high cation exchange capability to zeolite; hence it can be exchanged with organic and inorganic cations such as Rhodamine B dye [5]. 2. Experimental

In a synthesis, aluminumisopropoxide was first dissolved in TPAOH with stirring, followed by successive addition of NaOH and double distilled water. Then, TetraethylorthoSilicat (TEOS) and CoCl2 or FeCl3 solution was added in the above mixture with stirring and aged at ambient temperature (ca. 22 C) for 24 h. After 48 h of stirring under reflux, the synthesized gel was shaked at ambient temperature. The synthesized zeolite was calcinated in an electrical furnace at 550 ºC for 5 h to remove of organic template. XRD patterns were recorded by X-ray diffractometer (XRD, GBC−MMA) with Be Filtered Cu Kα radiation (1.5418 Å)operating at 35.4 kV and 28 mA. Scanning electron microscopy (SEM, VEGA2−TESCAN) was employed to study morphology and size of obtained crystal.Fourier transform infrared (FT-IR)spectrum was recorded at room temperature using Bruker FT-IR spectrometer. Removal of Rhodamine B from wastewaters was performed by modified ZSM-5 nanozeolite using Uv-vis technique in an aqueous medium at a maximum wavelength (λmax) of 548 nm. 3. Results and Discussion

Wedeveloped an effective method for the synthesis of ZSM-5, Fe-ZSM-5 and Co-ZSM-5 nanozeolite. The structure of synthesized nanozeolite was characterized by XRD, FT-IR, and SEM technique. Fig. 1 illustrates XRD powder pattern together SEM image of ZSM-5 nanozeolite. Results indicated that the pure ZSM-5 nanozeolite was obtained with comparing the main peaks at 2 = 7.9, 8.9, 23.2 and 24.5 degrees with the reference sample [6]. Inset in Fig. 1 shows SEM image of synthesized ZSM-5 nanozeolite, which the formation of spherical nanosized particle can be observed with average diameter of 97 nm.Also, average diameters of 67 and 63 nm were obtained for the synthesized Co-ZSM-5 and Fe-ZSM-5 zeolite.


Fig. 1.XRD pattern of ZSM-5 nanozeolite. Inset shows SEM image of this sample.

Removal of Rhodamine B dye from wastewaters was performed by modified ZSM-5 nanozeolite using

Uv-vis technique.Batch experiments were carried out to measure the adsorption value as a function of contact time (20–100 min), initial dye concentration (25–35 mg/L), pH (3–11), sorbent dosage (0.005–0.04g), mixing rate (150–200 rpm) and temperature (298–348 K).Results indicated that the synthesized Fe-ZSM-5 and Co-ZSM-5 nanozeolite can be utilized as a good adsorbent for Rhodamine B dye. Also, Results indicated that the Fe-ZSM-5 and Co-ZSM-5 nanozeoliteas an adsorbent was found to increase efficiency of Rhodamine B adsorption as compared to the unmodified ZSM-5 nanozeolite. Adsorption isotherms were fitted with the Langmuir and Freundlich models that well matched with Freundlich model. References [1] O. Ozdemir, B. Armagan, M. Turan, M. S. Celik, Dyes Pigm.(2004) 49. [2] S. Wang, H. Li, S. Xie, S. Liu, L. Xu, Chemosphere.(2006) 65. [3] S.B. Wang, Y. Boyjoo, A. Choueib, Z.H. Zhu,Water Res. (2005) 39. [4] S.M. Dal Bosco, R.S. Jimenez, W.A. Carvalho, J. Colloid Interface Sci. (2005) 281. [5] R. Han, Y.Wang, W. Zou, Y. Wang, J. Shi, J. Hazard. Mater.(2007) 145. [6]A. Gurses, C. Dogar, M. Yalc, M. A. kyldz, R. Bayrak, S. Karaca,J. Hazard. Mater. 131 (2006) 217.


Utilization of natural zeolite in improving the living environment

M. Jahangiri*, A. Ebrahimi, A. Aminian

Chemical, Oil and Gas Engineering Department, Semnan University, Semnan *Corresponding author: [email protected]

1. Introduction The population growth in the urban areas, the oil and goods transportation, the emissions from vehicle exhausts, the mining and smelting activities, the energy production, and the, frequently uncontrolled, use of pesticides resulted in the accumulation of huge amounts of hazardous inorganic and organic pollutants in the environment. Severe environmental contamination has also been observed in cases nuclear reactors accidents, explosions in nuclear waste storage facilities and in the surroundings of a number of military and civil fuel reprocessing plants around the world. When the concentration of the pollutants exceeds certain limits and their presence seriously endangers the environment and the human health, remediation actions are necessary. The remediation can mainly be based on two approaches: the extraction of the pollutants from the soils or aqueous systems or the reduction of their mobility and/or their in situ stabilization [1]. This contribution will provide an short review of the most recent applications of natural zeolites and their modified forms to the separation, binding and chemical stabilization of hazardous inorganic, organic and radioactive species in soils and aqueous systems, the treatment of acid mine, industrial and municipal effluents and the pedotechnical restoration. 2.Experimental Utilization of natural zeolites in environmental remediation Multicomponent sorption experiments and thermodynamic calculations were also performed in several cases [2]. However, the thermodynamic calculations in the case of natural zeolite materials are not always simple because of their composition complexity (e.g. the presence of other sorbing phases, varying zeolite content, etc.). The application of natural zeolites to the environmental remediation is not new and a number of articles and books have appeared on this subject [3]. However, the intense investigation of the natural zeolites properties started in the middle of the previous century, when materials with enhanced sorption capacity were necessary for the nuclear waste management. Natural zeolites are used for the purification of water [4]. It is also worth noting that the use of natural zeolite (clinoptilolite) in the Sellafield Ion Exchange Effluent Plant (SIXEP), since 1985, had reduced the concentration of 137Cs and 90Sr in effluent stream discharges to the Irish Sea to relatively constant low levels. Regions rich in natural zeolites (e.g. Yucca Mountains, Nevada, USA) were also proposed as potential waste repositories. Clinoptilolite efficiently adsorbed Cu2+, Fe2+, Al3+, and Zn2+ within 20–30 min. Stability tests were carried out for pH from 1 to 5 to determine the leaching of these ions from clinoptilolite. After acid treatment at pH 2, the clinoptilolite released significant amounts of Al, Fe, Na and K cations. XRD patterns revealed that clinoptilolite treated at pH 1–5 for 144 hr had similar diffraction patterns and minimal change in crystallinity. At low pH, clinoptilolite might dissolve only at the surface. Clinoptilolite appears to be a good candidate for acid rock drainage (ARD) treatment. Zinc uptake by adsorption from zinc-spiked ARD on natural clinoptilolite was investigated in a slurry bubble column [5]. Natural zeolite was added to artificially pollute garden soil to immobilize and limit the uptake of lead by rape through changing soil physical and chemical properties in the pot experiment under greenhouse conditions.


3. Result and discussion Results indicated that the addition of natural zeolite could increase soil pH, CEC, content of soil organic matter and promote formation of soil aggregate. The application of zeolite decreased the available fraction of Pb in the garden soil by adjusting soil pH rather than CEC, and restrained the Pb uptake by rape. Experiments have suggested that the application of a dose of zeolite (≥10 g/kg) is significantly reduce the soluble lead, even if lead pollution is severe in garden soil (≥1000 mg/kg). An appropriate dose of zeolite (20 g/kg) could reduce the Pb concentration in the edible part (shoots) of rape up to 30% of Pb in the seriously polluted soil (2000 mg/kg). The removal or stabilization of heavy metals, e.g., lead, in environmental matrices is the object of the numerous of investigations that recently appeared in the literature. Phillipsite and faujasite were successfully used to stabilize lead, cadmium and nickel in contaminated soils [6]. The mixed treatment (zeolite and humic acids) of artificially Pb-polluted garden soil resulted in significantly greater reduction in the lead concentration in plants compared to the addition of single zeolite but slightly increased the water-soluble fraction of lead compounds in the soil. Laboratory-scale investigations and field tests indicated the effectiveness of natural and modified zeolites to reduce the concentration of heavy metals and hazardous substances in plants. This also has as consequence the limitation of the ground erosion. Clinoptilolite was studied as sorbent of lithium for the protection of poplar plants grown in the contaminated soil. Lithium was selected as a model contaminant as it could be tracked directly using nuclear magnetic resonance. Studies utilizing Neapolitan Yellow Tuff (NYT) in abating soil Cu-, Pb-, and Zn- toxicity against living organisms also showed that the presence of the zeolites restored a friendly to biota soil environment, by leading to a substantial recovery of the fertilization success and of the vitality, with a concurrent significant reduction of pathologies and mortality. The pedotechnical applications of zeolites/organic mixtures and their synergy to phytoremediation are a subject of continuous intensive investigation, which will gain further importance in the future. However, there is only limited information in the literature about the potential disadvantages of the long-term application of natural zeolites. Their influence on the soil pH, essential metal availability, the possibility to release considerable amounts of sodium, and the long-term binding of polluting metals in the soil were just a few of the problems pointed out . The purification of water and industrial wastewater treatment are further fields of application of natural zeolite materials. Adsorption techniques are widely used to remove certain classes of pollutants from water, especially those that are not easily biodegradable. Dyes represent one of the problematic groups. Natural zeolite was also used as a low-cost adsorbent to evaluate its ability to remove color from effluents [7]. The improvement of the long-term chemical and physical stability of the modified zeolite-based materials and the combination of their sorption properties with the contaminant destruction can also be subject of further academic and industrial research. Finally, the consideration of the treatment, disposal or regeneration of the contaminant-loaded zeolitic forms will also definitively increase their environmental application possibilities. References [1] W.Y. Shi, H. Shao, H. Li, M. Shao, J. Hazard. Mater., 161 (2009) 633–640. [2] R. Petrus, J.K. Warchoł, Water Res., 39 (2005) 819–830. [3] C. Colella, J.C. ejka, H. van Bekkum, Stud. Surf. Sci. Catal., 168 (2007) 999–1035. [4] E.H. Borai, R. Harjula, L. Malinen, A. Paajanen, J. Hazard. Mater., 172 (2009) 416–422. [5] T. Motsi, N.A. Rowson, M.J.H. Simmons, Int. J. Miner. Process., 92 (2009) 42–48. [6] H. Li, W.Y. Shi, H. Shao, M. Shao, J. Hazard. Mater., 169 (2009) 1106–1111. [7] Y. Zhao, T. Gao, S. Jiang, D. Cao, J. Environ. Sci., 16 (2004) 1001–1004.


Effect of temperature and loading on the Diffusion of in ISV-type zeolite: A molecular dynamics simulation

Hossein Mohammadi-Manesh,a,* Mohammad Mohsen Loghavib

aDepartment of Chemistry, Yazd University, Yazd, P. O. Box 89195-741, Iran bIranian Space Agency, Engineering research institute, Fars Engineering Research Center, Shiraz,

71555-414, Iran *Hossein Mohammadi-Manesh. 0351-8122646, 0351-8210644, [email protected]

1.Introduction

Diffusion and adsorption of different molecules in zeolites have received a lot of attention in the last few decades. As most of the activity occurs inside the material, it is very difficult to carry out experiments that provide us information at the molecular level. Molecular dynamics simulations are used to give a comprehensive view of adsorption, diffusion and loading selectivity of carbon disulfide gas in ITQ-7 zeolite. A molecular dynamic computation consists of analyzing the evolution of the sample with time. In the case of a molecule, the atoms that form it are continuously moving, the bonds are vibrating, the angles are bending, the whole molecule is rotating, etc. If we were able to follow the exact position of every atom as a function of time, we could build a table with the coordinates of each atom in the molecule as a function of time and use it to calculate properties that depend on the conformation of the molecule. ITQ-7 (structure type ISV) has a three-dimensional system of large pores defined by windows containing 12 member rings of about 6 Å in diameter [1]. , is very toxic and is harmful by inhalation of the vapor, skin absorption of the liquid, or ingestion [2]. Molecular dynamics simulations were performed for the ITQ-7 super cells at loadings of 2, 4, 6, 8, 10, 12, 14 and 16 molecules per unit cell and different temperatures-200, 298, 400, 500, 600 and 700 K- via the DL_POLY program version 2.18. We calculated quantities such as diffusion coefficients, activation energies, binding energies and RDfs. Results show the diffusion increases with increasing temperature and decreasing loading.

2.Experimental Siliceous zeolite -ITQ-7- and carbon disulfide have been chosen as the host and guest, respectively. Interactions between adsorbed molecules and the zeolite framework atoms have been modeled by method of Makrodimitris et al [1] and Rabinson et al [2]. That is, each atom in the zeolite is assumed to interact with each site on the adsorbed molecules through both a Lennard-Jones potential and electrostatic interactions. Cutoff distance of 13 Å was used for all simulated systems. The electrostatic interactions were evaluated using the Ewald method with a precision of 1×10-6. Molecular dynamics simulations were performed on the periodic 3×3×3 replica of the ITQ-7 unit cell at loadings of 2 to 16 muc and different temperatures-200 to 700 K- via the DL_POLY program version 2.18. Periodic boundary conditions were applied and the time step and pressure in all simulations were 1 fs and 1 bar, respectively. Each MD simulation started with an equilibration (300 000 time steps in the NVT ensemble) followed by MD runs (500 000 time steps) in the NVE ensemble for data collecting.

3.Results and Discussion The MSDs for center of mass of in ITQ-7 were calculated at the different loadings as a function of temperature in the range of 0–480 ps. At all of these loadings, the MSDs increase with temperature. The diffusion coefficients have been evaluated from the linear slope of MSD (t) functions in the diffusive regime [3]. Figure 1 illustrates these coefficients as a function of the temperature and loading. As seen in Figure 1, the diffusivity increases as the temperature is increased, due to the increase of mobility of particles. The guest diffusivity in ITQ-7 decreases with increasing loading because of mutual hindrance. Diffusion activation energy is obtained as the slope of ln(D) vs 1/T plot at each loading [4]. These activation energies are about 5.4 kJ/mol at most loadings except of 2 and 4 loadings. The radial distribution functions (RDFs) were calculated at several temperatures and loadings for C-C, Si-C and O-C sites. The RDFs of C-C


were changed with increasing temperature and loading, while RDfs of Si-C and O-C remains nearly constant, because Si and O atoms were frozen in the simulations.

Figure 1. Effect of temperature and loading on the diffusion coefficient of in the zeolite.

The binding energies [5] per guest molecule at all loadings were calculated. As seen in Table 1, these energies increase as a function of loading for the presence of more number of guests. The adsorption energies decrease with temperature for the increase of kinetic energy of the molecules. Table 1. Calculated binding energies at different temperatures and loadings (kJ/mol) loading (muc) 200 K 298 K 400 K 500 K 600 K 700 K

2 -31.93 -30.27 -26.83 -25.21 -25.43 -25.91 4 -32.86 -29.34 -27.76 -27.06 -27.28 -24.91 6 -33.79 -30.88 -29.30 -28.91 -27.90 -26.14 8 -35.64 -31.61 -30.36 -29.84 -28.67 -27.69

10 -36.01 -32.86 -31.65 -31.50 -30.25 -28.61 12 -36.56 -33.97 -33.00 -32.31 -31.61 -29.85 14 -37.75 -35.82 -34.50 -33.41 -32.58 -30.46 16 -39.11 -37.44 -35.86 -34.47 -32.84 -31.85

References [1] K. Makrodimitris, G. K. Papadopoulos, D. N. Theodorou, J. Phys. Chem. B, 105. (2001) 777-788. [2] S. B. Zhu, J. Lee, G. W. Robinson, Molecular Physics, 65. (1988) 65-75. [3] M. H. Kowsari, S. Alavi, M. Ashrafizaadeh, B. Najafi, the Journal of Chemical Physics, 129. (2008) 224-508. [4] P. Demontis, G. B. Suffritti, Chem. Rev. 97. (1997) 2845-2878. [5] A. Sirjoosingh, S. Alavi, T. K. Woo, J. Phys. Chem. C, 114. (2010) 2171–2178.


Zeolite-based catalysts in process industries

Mansour Jahangiri*, Ali Aminian

Chemical, Oil and Gas Engineering Department, Semnan University, Semnan

*Corresponding author: [email protected]

1.Introduction Zeolite catalysts are capable of cracking large hydrocarbon molecules, and allow valuable primary cracked products, like gasoline and diesel molecules, to more readily escape the catalyst before they are overcracked to less valuable light gases and coke. Since the introduction of zeolite-based catalytic cracking in the 1960s, zeolite-Y has been the active ingredient of choice. It is relatively stable at the high temperatures within the fluid catalytic cracking (FCC) unit and very efficient at catalyzing the cracking of smaller FCC feed molecules that can enter through its micro-pores. However, larger product molecules are a tight fit within zeolite pores and can take a relatively long time to leave the zeolite crystal. During that relatively long stay within the micropores, such valuable products can be recracked to less valuable gases and coke. Martinez and Ying [1] had modified the micro-pores structure of zeolite-Y that it can improves the movement of molecules by creating a network of intermediate sized (2-6 nm) mesoporous throughout the crystals of zeolite-Y. These “molecular highways” admit and pre-crack even the largest feed molecules, while also channeling product gasoline and diesel molecules safely out of the zeolite. The size and volume of mesopores created in zeolite-Y can be controlled over a fairly wide range by growing the zeolite around templates. The most important application of zeolites as catalysts in process industries are hydrocracking of heavy petroleum distillates [2], octane number enhancement of light gasoline by isomerization [3], the synthesis of ethylbenzene (the precursor of styrene and polystyrene) from benzene and ethene [4], the disproportionation of toluene into benzene and xylenes [5] and the isomerization of xylenes (to produce paraxylene, the precursor chemical for terephthalic acid). Surface acidity and shape selectivity of zeolites makes them usefule as catalysts in chemical process industries. Zeolite structure Zeolites are aluminosilicate framework structures made from corner sharing SiO4 and AlO4 tetrahedra (Fig.1). Zeolite-Y (FAU) is a three-dimensional zeolite with large cavities present in the structure that are interconnected by 12 membered ring (MR) channels. The framework of a zeolite contains channels, channel intersections and/or cages. The zeolite structure consists of a pore system with channels in one, two or three dimensions and additionally inner cavities may be present. The diameters of the pores and cavities range from 3 Å to 12 Å, which coincides with the dimensions of many hydrocarbon molecules for which they are applied as adsorbents and catalysts. Another zeolite containing 10 MR channels is ZSM-5 (MFI). For this zeolite the straight 10 MR channels are interconnected by 10 MR zig-zag channels, which makes this zeolite three dimensional. Zeolite catalysts Compared to other types of catalysts, zeolites exhibit exceptional properties with respect to both activity and selectivity because of their ability to adsorb and transform molecules in their inner pore volume.


Figure 1: Zeolite structures Zeolite-Y is of utmost importance in heterogeneous catalysis due to its pore system, referred to as supercage, with diameter of 1.3 nm. ZSM-5 is another gained huge importance in heterogeneous catalysis. It is used industrially in the synthesis of ethylbenzene, the isomerization of xylenes and the disproportionation of toluene. Zeolites are used in process industry in these main processes: – FCC unit Zeolite-Y, ZSM-5 – Deep Catalytic Cracking (DCC) ZSM-5 – Shape-selective cracking ZSM-5 – Hydrocracking Zeolite-Y, ZSM-5 – Catalytic dewaxing ZSM-5 – Isomerization of C4 olefins Ferrierite (FER) – Hydroisomerization of low paraffins Pt/Mordenite (MOR) – Isomerization of xylenes ZSM-5, MOR – Aromatization of C3/C4 ZSM-5 – Methanol to Gasoline process ZSM-5 – Methanol to Olefin process ZSM-5 Conclusion Zeolites are important materials with very broad catalytic applications. Today, mainly synthetic zeolites are used widely in petroleum refining and chemical processes as selective adsorbents, catalysts, and ion exchangers. Catalysis is one of the most important fields of application of zeolites, but by no means the sole one. Large efforts are being undertaken worldwide to open the door to novel applications for zeolites. References [1]. J.Y. Ying, J.G. Martinez, US Patent 7589041, 2009. [2] J. Scherzer, A.J. Gruia, Hydrocracking Science and Technology, Marcel Dekker, New York, Basel, Hong Kong, 1996, pp. 305. [3] S.T. Sic, Handbook of Heterogeneous Catalysis, G. Ertl, H. Kndzinger, J. Weitkamp (Eds.), Wiley-VCH, Weinheim, Vol. 4, 1997, pp.1998. [4] F.G. Dwyer, Catalysis of Organic Reactions, W.R. Moser (Ed.), Marcel Dekker, New York, Basel, 1981, pp. 39. [5] N.Y. Chen, W.E. Garwood, F.G. Dwyer, Shape Selective Catalysis in Industrial Applications, Marcel Dekker, New York, Basel, 1989, pp. 203.


Efficiencyof Zeolite-based Materials for Gas Sensors

Mehdi MalekAlaiea , Mansour Jahangiryb*

a,bSemnan University , School Of Chemical Engineering , Oil and Gas , Semnan , Iran

*[email protected]

1.Introduction Modern sensors are becoming increasingly important as key components in the progressive automation of industrial processes. In recent years the material class of zeolites has received increasing attention within the field of gas sensing.. Some applications of zeolite materials in gas sensors have been developed based on thecharacteristics mentioned above: 1) Assembly of a compound specifically sensing a gas into zeolite cages or channels 2) Fixing of zeolites on quartz crystal microbalances (surface acoustic-wave, micro cantilever, or optical fiber) for sensing some gases by selective absorption; 3)Changing the conductivity of zeolites due to the absorbance of some gases for making sensors based on impedance spectroscopy measurements; 4) Placing zeolites onto sensors as filter materials for enhancing the selectivity to a certain gaseous molecule; 5) Immersing zeolites into some materials or supports forming composites for making sensors, such as the conductivity of polyaniline/zeolite composites responsive to CO, SnO2/zeolite composites responsive to H2 and CO [1]. This brief review deals with the uses of zeolites and zeolite-based materials for developing gas sensors 2.Application Hydrocarbon Sensors It is shown that the principle of functioning of the hydrocarbon sensor recently described is not based on a new sensing effect but is the same as that of a solid state sodium concentration cell acting as an oxygen gas sensor in the presence of oxidizable gases. The particularities in the behavior of the sensor are due to the electronic conduction properties of the solid electrolyte and the thermodynamic stability of the zeolite [2].Gas sensors of Pd-doped SnO2 semiconductor covered with zeolitic films (MFI or LTA type) have been prepared and used for detecting different species (methane, propane, and ethanol) at different humidity levels. The dynamic responses presented by these sensors were compared with that of a reference sensor without the zeoliticlayer[3]. A P-type semiconductor family of SrTi1-xFexO3-delta with a perovskite structure has been used as the base material for a hydrocarbon sensor. A cover layer made of platinum-doped zeolite with catalytic activity has been proven to have an effect for reducing the cross-interference influence of some species[4]. Ammonia gas sensors The electrical conductivity sensitivity of 50:1 dPPP toward NH3 decreases withincreasing NH3 concentration and can be further improved by introducing a ZSM-5 zeolite into the dPPP matrix. The electrical conductivity sensitivity decreases with increasing zeolite content up to 30%. At 40% zeolite content, the positive response is present at the beginning of the gas exposure and the negative response appears at later times [5]. A zeolite-containing coating on a surface-acoustic-wave (SAW) sensor was also developed for detecting ammonia. The frequency of the SAW sensor increases in the reaction of ammonia in a humid atmosphere with the zeolite-containing coating. In ambient air with humidity higher than 10%, a selective determination of ammonia was provided at a level of tenths of a percent [6]. Carbon Monoxide Sensors The sensor based on the ceramic coated with the zeolite presents high selectivity towards CO among H2, CH4, i-C4H10, C2H4, and C2H5OH. As a result, a CO selective gas sensor was obtained, which has a


sensitivity towards CO over ten times higher than that towards other gases at about 573K [7]. The material exhibits an electrical conductivity response to CO, which is related to the content, pore size and ion exchange capacity of the zeolite, dopant type and concentration. adding 40% w/w of NaA (4Å) zeolite reduces the electrical conductivity response, but improves the sensitivity towards CO [8]. Humidity Sensors Films of LTA type zeolite on mass sensors (quartz crystal microbalances) were prepared and used for humidity microsensors. The zeolite’s films are hydrophilic, thermally stable, and show reproducible responses. These films can be used effectively as humidity sensor materials for water vapor sensing purposes. High sensitivity, good reversibility, and long film life have been demonstrated at low steam concentrations [9]. An optical reflectance sensor has been developed based on the solvatochromic Nile Red immobilized within NaY zeolite supercages. The sensor performance has been tested with water and n-hexane vapors. The Nile Red−Y composite exhibits excellent properties as humidity sensor in terms of sensitivity (much lower than 200 ppm), response time (around 4 min), and dye stability toward migration upon high light exposures [10]. Sulfur Dioxide Sensors A thin layer of FAU type zeolite was synthesized on the QCM with an Au electrode, and applied as a SO2 gas sensor. When SO2 gas molecules are adsorbed on the zeolite layer, the mass increase reduces the frequency of the QCM. The frequency shift of the QCM is proportional to the mount of SO2 adsorbed, resulting in a use for measuring the gas-phase concentration [11]. 3. Conclusions Due to high and selective absorption properties of zeolites towards a specific gas greatly enhance the sensing selectivity for the gas. The compound or cluster sensing towards a gas assembled into the cages or channels of zeolites results in its high stability, and maximally elevate the sensing property of the materials.

References

[1] C.Gottert, D. Schneider, D. Knorr , Journal of Catalysis 2008, 255, 68-78 [2] H.Näfe ,ElectrochimicaActa (2007) Volume: 52, Issue: 28, Pages: 8167-8172

[3] K.Sahner, R.Moos, , Sensors and Actuators B-Chemical 2008, 133, 502-508. [4] X.Xu, J. Wang, Y. Long.. Sensors 2011, 6, 1751-1764. [5] P. Phumman, S. Niamlang , Sensors 2009, 9, 8031-8046.

[6] G.Hagen, A. Dubbe, F. Rettig, A. Jerger, T. Birkhofer, R. Müller, C. Plog, Sensors and Actuators B-Chemical 2006, 119, 441-448.

[7] I.G.Giannakopoulos, D.Kouzoudis, C.A Grimes,. Adv. Funct. Mater. 2005, 15, 1165-1170. [8] V.Granda, M. Pérez-Cordoves, A.I. Díaz-García, .Trac-Trends Anal. Chem. 2009, 25, 24-30. [9] D.PMann ,K. Pratt, I.P Parkin Sensors Journal 2010, [10] R.Moos, K. Sahner,. Rare MetalMaterials And Engineering 2006, 35, Suppl. 3, 447-451. [11] J.Trimboli, P.K. Dutta, Sensor. Actuator. B-Chem. 2009, 102, 132-141.


On the synthesis and application ofMesoporous materials

Ali AminianMansour Jahangiri*,

Chemical, Petroleum and Gas Engineering Department, University of Semnan, Semnan

*Corresponding author: [email protected]

1.Introduction The molecular sieves namely zeolites and microporous materials have pore size in the range of sub nanometers that limits their application to small molecules. On the other hand, mesoporous materials overcome the pore-size limitation of zeolites and microporous molecular sieves. The meso pores allow many reactions on ordered porous materials to be possible. The big advantage of the ordered mesoporous material is that it has a high surface area and a large pore volume. Zeolites and microporous molecular sieves had developed via mesoporous material synthesis. It starts from silicate and aluminosilicate, through substitution of their molecules to other oxide and sulfide compounds. Many unavailable forms of zeolites can be made in mesoporous material form. For example, mesoporous silica-based material can be synthesized through hydrolysis of tetraalkylorthosilicates in the presence of a cationic surfactant [1,2]. The basic synthesis routine for mesoporous materials contains four major components: inorganic precursors, organic template molecules, solvent (water), and acid or base catalyst [3].The desired morphology of the material can be attained by controlling the reaction conditions. For example, temperature and concentration of the surfactant are the main factors can affect the micelle phase formation [4]. In addition, the micelle phase possesses very strong template effects. In general, the interaction between organic template and inorganic species is the key to mesoporous material synthesis. In an effort to develop selective solid adsorbents for acidic gas removal from natural gas mixtures, amine-modified mesoporous silica materials have been applied. Also, metal or metal-oxide-based gas sensors are the most widely used solid-state devices for detecting gases in the environment. The high specific surface areas and uniform meso-pores of mesoporous materials will result higher probability for a gas to interact with the sensing compounds or sides, which is likely to increase the sensitivity of the materials. On the other hand, conventional Zeolite-based materials have been used as a compound in hydrocracking catalysts for about 40 years. Other important refinery applications, where zeolites are used, are fluid catalytic cracking, isomerization, dew axing and aromatics saturation [5].An interesting alternative might be to use zeolite-based catalysts for exhaust gas treatment. The new zeolitic catalysts were not only orders of magnitude more active thanthe previously used amorphous silica-alumina catalysts, but they also brought about a significant increase in the yield of gasoline, the most valuable product from fluid catalytic cracking units [6]. Zeolites with good selectivity's have used to remove Cs and Sr from radioactive waste streams. This review will focus on the synthesis routes and application of zeolites and related mesoporous materials. 2. Synthesis Interaction between template and inorganic species The interaction between organic template and inorganic species can be found from different organic-inorganic combinations. For instance, interaction between surfactant and inorganic precursor can be modified by adjusting the surfactant polar head. Thus, the strength of interaction between any kinds of components have an effect on the final form of the synthesized product. A better understanding of the formation mechanism via combined characterization techniques and modeling may lead to a more


rational approach for adjusting the pore size of mesoporous materials. Pore size and shape can be controlled by growing the mesoporous around templates. By changing the size and volume of micelles, pore size of the meso-structured materials can be controlled. The tail length of surfactant, mixture of surfactants, concentration of surfactant, cationic surfactant, hydrothermal treating after synthesis process can be used to control the pore size of mesoporous materials. In comparison to zeolites, ordered mesoporous materials overcome the pore-size limitation of zeolites and allow easier diffusion of molecules. Mesoporous oxides have been used as supports for metals and metal oxides. In reactions that require milder acidity and also involve bulky reactants and products, mesoporous materials exhibit great potential [7, 8]. 3. Result and discussion Initially, a research group in japan carried out the synthesis of ordered mesoporous materials. The basic synthesis method is generalized into a sol-gel method. Synthesis method of mesoporous material can be classified into heating methods, surfactant effect, post-synthesis hydrothermal treating and synthesis conditions. Most of mesoporous materials were synthesized using ionic or neutral surfactants as templates for directing the formation of mesoporous, which relied on the self-assembly of the surfactants and the interaction between the inorganic precursors and the aggregates. The pore diameter of the mesopores could be controlled by the hydrophobic alkyl chain length of ionic surfactants and/or with the aid of auxiliary organic compounds as additives, spacers and pore fillers [3,5]. Because of the strong electrostatic interactions between the ionic surfactants and the inorganic precursors, the ionic templates were usually removed by calcination.With successes in the synthesis of various mesoporous materials, we have reason to expect that further application possibilities coming soon. Formation of mesoporous in a single step process is economically attractive, as it decreases the amount of time and labor required for obtaining the product. The use of single template for the synthesis is another important factor that would further decrease of the production costs. Also, the active templating synthesis method of mesoporous materials without surfactants is the active area of the researches. References [1]. V. Chiola, J.E. Ritsko, C.D. vanderpool, US patent, Vol.3, 556, (1971). [2]. M.E. Davis, ordered porous materials for emerging applications, Water, 417 (2002) 813-821. [3]. U. Ciesla, F. Schuth, ordered mesoprous materials, Microporous and mesoporous Mater., 27(1999) 131-149. [4]. Q.S. Tluo, D.I. Margolese, G.D. Stucky, surfactant control of phases in the synthesis of mesoporous silica-based materials, chem. Maters., 8(1996) 1147-1160. [5]. T. Beiw, Synthesis and application of molecular sieve layers and membranes. Chem. Maters., 8(1996) 1636-1653. [6]. R. von Ballmoos, D.H. Harris, J.S. Magee, in: G. Ertl, H.Knbzinger, J. Weitkamp (Eds.), Handbook of HeterogeneousCatalysis, Vol. 4, Wiley-VCH, Weinheim, 1997, p. 1955. [7]. A. Taguchi, F. Schuth, Ordered mesoporous materials in catalysis, Microporous. Mesoporous. Maters., 77 (2005) 1-45. [8]. A. Corma, From Microporous to mesoporous molecular sieve materials and their use in catalysis, Chem. Rev., 97 (1997) 2373-2419.


Synthesis of thiol-functionalized hierarchical mesoporouszeolitesand its application in heavy

metals removal

O.Fardmousavia, H.Faghihian*b a,bShahreza Branch, Islamic Azad University,Esfahan, 86145-311, Iran

*Corresponding author. Tel:0321-3292514,E-mail address:[email protected]

1. Introduction

Heavy-metal ions in the natural environment arise from both natural and anthropogenic sources, and can be harmful to human and living organisms. Among them, lead exhibits high toxic for both the environment and human health. Lead is present in the environment from urban wastes and industrial activities like the manufacture of storage batteries, painting pigments, ammunition, automobiles, cable coverings, radioactivity shields, and bearings. Although there are many traditional treatment methods, adsorption has proved to be one of the most feasible, simple, selective, cost-effective, ease of operation, and high-efficient process for the removal of heavy metals from polluted sources.Functionalized porous adsorbents have been widely used as solid-phase extractants for removal of heavy metals from aqueous media. Among them, thiol-functionalized silica was found to be efficient for the uptake of mercury(II), lead(II) species and many investigations have been devoted to the preparation and characterization of a wide range of polysiloxane-immobilized mercaptopropyl ligands, which were then applied to Pb(II) binding [1-6].

2. Experimental

2.1.Thiol-functionalized MCM-41/Beta preparation MCM-41/Beta composite was prepared as described earlier [2,4].The hierarchicalmesoporous zeolite was then refluxed in 250mL of toluene containing 3-mercaptopropyltrimethoxysilane at110 for 24 h. The solid was recovered by filtration and washed with toluene followed by ethanol. Any residual organosilane was removed by Soxhlet extraction over ethanol for 24 h[3,6]. 2.2. Lead adsorption isotherm 0.100 g of adsorbent was mixed with 50mL of lead (II) nitrate solution of known concentrationat different pH (1-5). The mixture was shaken for 24 h. The solid phase was separated by centrifugation and the supernatant solution was analyzed for lead concentration using atomic absorption spectrometery. The adsorption isotherms were then constructed by using different concentration of lead (50, 100, 150, 200, 250 and 300mg/L)[1].


The XRD pattern of the calcinedMCM-41/Beta nanoclustersshowedvery intense diffraction lines at 7.9° and 22.5°, which are the characteristic peaks of zeolite Beta (Fig 1-B). The characteristic line of MCM-41 was appeared at low angle (Fig 1-A), this line is disappeared when MCM-41 are combine with Beta zeolite because it is overlapped by the lines of this compound.


Fig 1.XRD of MCM-41(A)/Betazeolite(B) It was concluded from the adsorption experiments that the process was highly affected by pH of the media. At lower pHs because of high concentration of H3O+, the surface of adsorbent was protonated and hence the lead adsorption was limited. Whereas at higher pHs, the surface become negatively charged causing an attraction to positive Pb ion. The data of adsorption isotherms were fitted to Langmuir isotherm. References: [1] R. Rostamiana, M. Najafic, A. Rafati, Chemical Engineering Journal, 171 (2011) 1004-1011. [2] H. Xu, J. Guan, Sh. Wu, Q. Kan, Journal of Colloid and Interface Science, 329 (2009) 346–350.

[3]C. Delacôtea, F. Gaslainc, B. Lebeauc, A. Walcarius, Talanta, 79 (2009) 877–886.

[4]W. Guo, L. Huang, P. Deng, Z. Xue, Q. Li, Microporous and Mesoporous Materials, 44 (2001) 427-434.

[5]L. Wang, Z. Zhang, C. Yin, Z. Shan, S. Xiao, Microporous and Mesoporous Materials, 131 (2010) 58-67.

[6] H. Sepehrian, S. Waqif-Husain, M. Ghannadi, Chromatographia, 70 (2009) 277-280.


Preparation of alkylated amines over Nickel on silica-alumina nanocatalysts

Bahareh Tamaddoni Jahromi, Ali Nemati Kharat*

School of Chemistry, University College of Science, University of Tehran, Tehran, Iran

*+982161112499, +982166495291, [email protected]

1. Introduction

The N-alkylation of amines is an important reaction in organic synthesis. Alkylation with alkyl halides is the most conventional method [1] but it generates salts as by-products and exhibits often low chemical selectivity. Other reagents such as diazomethane or dialkylphosphites were also used for the same purpose but they are dangerous to handle or lead to purification problems. The reductive amination procedure is also a suitable method to perform N-alkylation with carbonyl compounds. Several reductors have been used among which hydrogen and sodium borohydride with titanium isopropoxide [2, 3]. Nevertheless, these conditions are not always selective for mono N-alkylation Of primary amines. Alcohols have also been used as alkylating agents with Ni [4] Rh or Ru catalysts [5, 6]. Here we report a selective method for the N-alkylation of amines (aromatic or aliphatic, mono- or di-alkylation) with a large scope of alcohols and amines, using the silica-alumina and Ni on silica-alumina nano-catalysts. A method for producing amines, comprising contacting at reactive conditions, a suitable alcohol, with an aminating agent in the presence of a nickel catalyst, is investigated by the catalyst being prepared by salt impregnation technique and subsequent reduction at hydrogen atmosphere.

2. Experimental

Preparation of catalyst: sodium aluminate is mixed with sodium silicate followed by adding nickel nitrate and ammonia under vigorous agitation to achieve a homogeneous mixture .The precipitate obtained is washed filtered and dried, it is then reduced in H2 in 450 ˚C. Catalytic application: Monoethanolamine, ammonia and the reduced catalyst is mixed, in the absence of air and placed in a high pressure autoclave. The reactor was charged with 350 psig and was heated to 175˚ C for 6 hours. After cooling the reactor, evacuation of the excess ammonia and hydrogen and drying the mixture, the reaction products were analyzed by gas chromatography equipped with a FID detector.


An amination catalyst has been found, catalyzing in particular ethanolamine-ammonia reaction with production of ethylenediamine, piperazine, and useful byproducts such as diethylenetriamine aminoethylpiperazine, aminoethylethanolamine, and hydroxyethylpiperazine. The amination catalyst is composed of an active element of the transition metal and is allied to a porous structure with a reasonable specific surface area. It is advantageous for elements of the catalyst to be co-precipitated from soluble salts. When the structure is formed by coprecipitation, the transition metals can be adjusted to the desired level. According to the impregnation version, the porous substrate composed of the mentioned oxides is made separately. The substrate is then impregnated with a soluble salt of the active element then, dried. The soluble salt is generally a nitrate. It is advantageous to pretreat the substrate by drying or degassing and impregnation conducted in a vacuum. Hence, the amount of active substance deposited is increased. The transition metal associated with the microporous substrate is subjected to direct reduction by a reducing gas.


Table1: BET Specific surface area and average crystal size of silica-alumina and Ni-silica-alumina

Catalyst BET surface area m2/g Total pore volume cm3/g Average pore diameter(nm)

Silica-alumina 277.57 0.4185 6.03

Ni-silica-alumina 57.268 0.1842 12.86

Table.1 shows the physical parameters obtained from nitrogen adsorption isotherms, such as the BET surface area, average pore diameter of Silica-alumina and Ni-silica-alumina. As expected, the total pore volume becomes slightly smaller as a result of immobilization of nickel. In conclusion we have described here a catalytic method suitable for the mono-or dialkylation of amines with cheap reagents. The catalyst does not undergo any changes. High temperature gas-phase catalysis can be applied successfully and studies are in progress to enlarge the scope of reactions in such conditions.

References

[1] Mohri K, Suzuki K, Usui M, Isobe K, Tsuda Y, Chem. Pharm. Bull, 43.(1995)159-161. [2] Fache F, Valot F, Milenkovic A, Lemaire M. Tetrahedron 52.(1996) 9777-9784. [3] Bhattacharyya S. Tetrahedron Lett. 35.(1994) 2401-2404. [4] Rice RG, Kohn E.J. J. Am. Chem. Soc. 77.(1955) 4052-4054. [5] Grigg R, Mitchell TRB, Sutthivaiyakit S,Tongpenyai N J. Chem. Soc., Chem. Commun. (1981) 611-612. [6] Baiker A, Kijenski J Catal. Rev. Sci. Eng. 27.(1985) 653-697.


Direct hydrothermal synthesis of hydroxysodalite crystals

Mohammad SadeghNabavi,aMansour KazemiMoghaddam a , TorajMohammadia* aResearch center for membrane separation process, Faculty of Chemical engineering, Iran

University of Science and technology, Narmak, Tehran, Iran.

*[email protected]

1.Introduction

Hydroxysodalite crystals were successfully synthesized using a direct hydrothermal synthesis method at temperature (100 °C) and one synthesis durations (15 h). The resulting crystals were characterized by X-ray diffraction (XRD). The XRD patterns revealed the successful formation of pure hydroxysodalite crystals.

2.Experimental

In order to prepare hydroxysodalite powder, the synthesis solution was obtained by mixing aluminate and silicate solutions in a polypropylene bottle.

In the first step, sodium hydroxide (18.79 g) (Merk) was dissolved in deionized water (78.35 g). Then the solution was divided into two equal parts and was put in two separated bottles. The aluminate solution was prepared by dissolving aluminate (0.85 g) (50–56% Al2O3, RiedeldeHaën) in the first bottle and the silicate solution was prepared by dissolving sodium silicate (2.004 g) in the second bottle. Next, the silica source was added to the alumina source quickly. The resulting mixture was stirred for half an hour in order to produce a homogenous clear solution. The molar ratio of the resulting synthesis solution was 2SiO2:Al2O3:55NaO2:1000H2O. The solution was poured in an autoclave and placed in an oven. The synthesis was carried out at temperature 100 °C for15 h.[1].


The temperature of synthesis is 100 °C and the time synthesis is about 15h were formed as the best temperature and time for synthesis of hydroxysodalite crystals.

as reported by other researchers[2] and based on our preliminary results, other temperatures and shorter and/or longer times may lead to form other zeolites, like A, - X, and -P in addition to hydroxysodalite.

The XRD reflections of the successful syntheses are given in Fig. 1.


Fig. 1- The XRD-pattern of hydroxysodalite crystals formed through directhydrothermal synthesis

References

[1] MansoorKazemimoghadam, TorajMohammadi,Separation of water/UDMH mixtures using hydroxysodalitezeolite membranes, Desalination 181 (2005) 1-7 [2] SheidaKhajavi∗, FreekKapteijn, Jacobus C. Jansen,Synthesis of thin defect-free hydroxysodalite membranes: New candidate for activated water permeation,Journal of Membrane Science 299 (2007) 63–72


Alcohol cyanoethylation with modified basic Na-Y nanozeolite

Sara Zamaniana,Ali NematiKharatb,* a,bSchool of Chemistry, University Collage of Science, University of Tehran, Tehran, Iran

*+982161112499, +982166495291, [email protected]

1. Introducton

Cyanoethylation is one of the important reactions for the synthesis of drug intermediates and organic compounds with industrial applications. In general, cyanoethylationcarryout in the presence of a basic catalyst. Cyanoethylation of alcohols with acrylonitrile form 3-alkoxypropanenitriles as a product. The reactivity orders are interpreted by the acidity of alcohol combined with the basic strength of the catalysts. Most of theso far reported catalysts are sensitive to air and moisture. Therefore, in this study, we picked up zeolites as more stable catalysts, and modified their basic properties with incorporation of Cesium and magnesium ions via ion-exchange and impregnation methods. We have compared the Cs-exchanged Y zeolite activity in the cyanoethylationof methanolbefore andafter impregnation with magnesium oxide. The best conversion was found with Cs-exchanged Y zeoliteimpregnated with MgO. 2.Experimental

Catalyst preparation: Cs-exchanged Y zeolites were prepared from its sodium formby ion exchange with the cesium chloride (catalyst A) or cesium carbonate (catalyst B) solutions at 70-80 OC.The time for a single exchange was around24 hours.These two samples were dried overnight at 100oC and calcined at 600oC for 4h .Catalyst B was then impregnated with slurry of MgO in ethanol for 15 minute in an ultrasonic bath. The solvent was removed by evaporation under vacuum. Sample C was prepared bydring overnight at 100oC of above catalyst and calcination at 600oC for 4 hours.Cyanorthylation reaction: Acrylonitrile, catalyst and excess amount of methanol were added into a RB flask and the mixture was stirred at room temperature for 24 h. After the completion of the reaction, the catalyst was separated from the mixture by centrifugation, and the reaction mixture was analyzed by using a gas chromatograph. 3.Results and Discussion Scanning Electron Micrographs (SEM) of the synthesized samples showed nano particles for cesium-exchenged zeolite Y (catalyst A) as shown below. Zeolites have pore diameters with one or more discrete sizes with pore diameters that are in the order of molecular dimensions, i.e., less than 1 nm. Therefore we can call zeolites, nano catalysts.

The reactivity orders are interpreted by the acidity of alcohol combined with the basic strength of the catalysts.The most active catalyst is sample C, among all the samples. Acrylonitrileconversion over the all samples was summarized in table 1.

Table 1: % conversion of acrylonitrile over prepared catalysts. Catalyst C Catalyst B Catalyst A

96 69 0 Methanol


As shown in table 1, the best conversion was found with using sample C as a catalyst. This catalyst has highest basic property among all samples. This result shows dispersion of MgO on the Cs-exchange Y zeolite (catalyst B) had favorable effects on increasing basic property as the conversionof acrylonitrile increase from 69 to 96.In the other hand, comparison of acrylonitrile conversions on catalyst A and B show, cesium carbonate is the better choice for Cs-exchange Y zeolite than cesium chloride.Thecatalytic activity of these catalysts for the other linear alcohols is in progress. References

[1] J.H. MacGregor, C. Pugh, J. Chem. Soc. (1945) 535-536. [2] W.P. Unlermohlen, J. Am. Chem. Soc. 67 (1945) 1505-1506. [3] H. Kabashima, H. Hattori, Catalysis Today, 44 (1998) 277-283. [4] H. Hattori, Chem. Rev. 95 (1995) 537-550. [5] H. Hattori, Applied Catalysis A: General, 222 (2001) 247–259.


Investigation the mobility of guest molecules in BEA zeolite by molecular dynamics simulation

Saeedeh Tashakor,a,* Hossein Mohammadi-Manesha

aDepartment of Chemistry, Yazd University, Yazd, P. O. Box 89195-741, Iran

* Saeedeh Tashakor. 0351-8122646, 0351-8210644, [email protected]

1.Introduction BEA zeolite is a tridirectional high silica zeolite that is formed by 12-membered-ring channels. This zeolite looks very favorable catalyst for the petrochemical and refining industries. BEA zeolite combines very good selectivity and activity characteristics. Due to diffusion of aromatic hydrocarbons in high silica zeolites like BEA zeolite is useful and some petrochemical processes involve the transformation of aromatic molecules through the pores of zeolites, we chose benzene as guest molecule. We prepared snapshots and Radial Distribution Function (RDF) of benzene in BEA zeolite at different temperature and loadings.

In the previous decades, many simulation techniques, such as molecular mechanics, molecular dynamics and Monte Carlo simulation have been applied to investigate the mobility and diffusion of guest in zeolite pores. Among them, the molecular dynamics (MD) technique gives access to time-dependent properties and is used for studying the diffusional behavior of guest, it means that this method allows the user to follow the time evolution of a model system over a given length of time. So this method gives a more detailed description of the adsorptive and diffusive processes and has shown to be successful in studying the diffusive behavior. 2.Computational and Methodology

The nine-site benzene model of Schroer and Monoson has been used to study the adsorption of benzene in BEA zeolite [1]. The intermolecular van der Waals potentials between atoms i and j on different molecules are considered to be the sum of Lennard-Jones (LJ) 12-6 and electrostatic point charge potentials centered on the atoms. To equilibrate the initial configurations, NVT MD simulations with the Nosé-Hoover thermostat-barostat algorithm have been performed on a periodic 333 replica of the tetragonal unit cell with the DL_POLY molecular dynamics program version 2.15. The simulations have done at a range of temperatures between 300 and 1000 K, at ambient pressure and at a loading 1, 2 and 3 of guest molecules per unit cell.

3.Result If we want to know how molecules move during the simulation, the best way is using of snapshot. For preparing snapshots we must know the situation of each molecule in each time step and then by using a software, snapshot are prepared. In this study snapshots were prepared by software that is called VMD.

Figure 1 indicates some of the prepared snapshots for the Center Of Mass (COM) of benzene. Temperature influences diffusion, we can realize this fact by focusing on snapshots that are given in Figure 1. These snapshots show that how increase in temperature causes diffusion be increased.

900 K

600 K

300 K

Figure1. Snapshots prepared without framework at loading 1 molecule per unit cell and 300, 600 and 900 K.


The Figure 2 displays the prepared snapshots with framework of zeolite. These snapshots display us that which parts of zeolite are occupied by guest molecule and which parts of zeolite are empty. These snapshots confirm the structure of BEA zeolite that is suggested by higness et al[1]. According to their suggestion the pore structure of BEA zeolite consists of channels along x- and y-axis. These channels are bilaterally orthogonal to the tortuous channel systems along z-axis. It is through the tortuous channels along the z-axis that molecules in the x-axis can move to y-axis.

900 K

600 K

300 K

Figure2. Snapshots prepared with framework at loading 1 molecule per unit cell and 300K.

Radial Distribution Function

In Figure 3 Radial Distribution Function (RDF) between center of mass of benzene and center of mass of benzene (com–com) obtained from simulation in BEA zeolite at loading 1, 2 and 3 molecules per unit cell and at 300 K and 900 K are shown. As it’s clear in this Figure at low temperature like 300 K, when loading increases due to the accumulation of molecules at higher loading is more, thus the height of the first peak goes up and its intensity increases. But at higher temperature like 900 K due to correlation between molecules is less so the concentration effect on RDF decreases.

Figure3. Radial distribution function of (com–com) of benzene at loading 1, 2 and 3 molecules per unit cell and at 300 K and 900 K.

Reference: [1] Ban, S.; Laak, A.N.C.van.; Jongh, P.E.de.; Eerden, J.P.J.M.van der.; Vlugt, T.J.H. J. Phys. Chem. C, 111.(2007), 17241.

[2] J. Higgins, R. LaPierre, J. Schlenker, A. Rohrman, J. Wood, G.T. Kerr, W. Rohrbaugh, Zeolites, 8. (1988) 446.


Synthesis and characterization of beta zeolite and its modification by phytic acid for removal of cadmium

SepidehNazariFarsani,aHosseinFaghihianb,* a,bDepartment of Chemistry, ShahrezaBranche, Islamic Azad University, 86145-311, Iran

Email: [email protected]

1.Introduction

Adsorption of the contaminants by a suitable adsorbent is one amongst the existing physicochemical methods, Due to the high surface area, and special structures and molecular-sized microporosity, zeolites are widely used as adsorbents in a variety of chemical reactions [1].Beta zeolite is the only high-silica zeolite possessing a three-dimensional system of large rings(rings of 12 oxygen atoms as the minimum apertures). Because of its efficacy, practicality, and economical feasibility, it has been frequently used in as adsorbent and catalyst. [2,3].In this work beta zeolite was synthesized by hydrothermal method. The synthesized zeolite was characterized and modified by phytic acid. The applicability of the adsorbent was studied for removal of cadmium which is often considered as the most biotoxic elements and it is regarded as a priority pollutant especially on account of its widespread anthropogenic sources in the environment.The results showed that the modified zeolite was a good candidate for absorption of the studied cation under optimal conditions.

2.Experimental

In this research, beta zeolite was firstly synthesized and characterized by X-ray diffraction and FT-IR techniques[4]. After modification with phytic acid, it was used for adsorption of Cd2+ from aqueous solutions. The effect of different parameters including pH, concentration on the adsorption was investigated and optimized.


Beta zeolite was synthesized successfully and its structure was characterized by XRD, FT-IR.

The adsorption capacity was as: beta zeolite – phytic acid >beta zeolite. Adsorption increased with increasing pH and concentration.The results indicated that the adsorption of Cd2+ ions on the surface of the adsorbents was depended on the solution pH. The adsorption removal of Cd2+ was maximum at pH=6.


Fig. 1. FT-IR spectrumof betazeolite.Fig. 2.XRD spectrum ofbeta zeolite.

Fig. 1.Dependence of Cd2+ adsorption on pH of Fig. 2. Dependence of Cd2+ adsorption on

solutions.concentrationofsolutions.

References

[1]S. Liu, Li. Chen, Yi . Wang, J.Solid State Sciences 12 (2010) 1070-1075.

[2] S.Loiha, S. Prayoonpokarach, P. Songsiriritthigun, J. Wittayakun, J.Mater Chem and Physics 115 (2009) 637–640.

[3]S. Simsek, U. Ulusoy, O. Ceyhan, " J. Radional. Nucle. Chem. 256 (2003) 315-321.

[4]Q-H. Xia, S-C. Shen, J. Song, S. Kawi, K. Hidajat, J.Catal, 219 (2003) 74-84.


Sulfate membrane electrode containing modifiednano-clinoptilolite with

tetradecyltrimethyl ammonium bromide surfactant

AlirezaNezamzadeh-Ejhieh*, Maryam Danesh

Department of Chemistry, Shahreza branch, Islamic Azad University,P.O Box 311-86145,Shahreza,Isfahan,Iran

E-mail: [email protected]

[email protected]

Abstract

A selective membrane electrode based on surfactant modified zeolite showed very good

selectivity forsulfate anions over a wide variety of common inorganic and organic anions. The

sensor displayed a Nemstian slope of -29.9± 0.4 mVper decade of the sulfate concentration. The

response of the sensor to sulfate remained constant in the pH range of 2.0 – 10. The best

performance was obtained with a membrane composition in the ratio of 32% PVC, 64% dioctyl

phthalate and 4% surfactant modified zeolite (SMZ).The sensor was highly selective for sulfate

over a wide variety of other anions and exhibited a rapid response time of< 10 s over period of 2

months with good reproducibility. Thus, this novel sensor may be applied as an indicator in the

potentionmetric titration of sulfate [1].

Keywords:Nano-clinoptilolite, Surfactant modified zeolite, Potentiometry

References:

[1] A. R. Nezamzadeh, A. Badri, Surfactant modified ZSM-5 zeolite as an active component of

membrane electrode towards thiocyanate, Desalination 281 (2011) 248-256.


Application of modified zeolite in measurement of mercury released from dental amalgam

to the urine by combined solid phase extraction and cold vapor atomic absorption spectrometry.

E. Faghihiana and H. Faghihianb*

aFaculty of Dentistry, Medical University of Isfahan, Isfahan, Iran b*Department of Chemistry, Isfahan University, Isfahan, Iran Corresponding author, 0311-7932716, [email protected]

1.INTRODUCTION Dental amalgam is a mixture of about 50% mercury by weight with an alloy powder containing mainly silver, tin and copper. The composition of the alloy varies between different manufactures. The alloy may also contain smaller amounts of zinc, indium, palladium, and platinum. A reference value of 5 µg Hg/kg has been considered normal for the general population not subjected to occupational exposure. Recently, the Food and Agriculture Organization of the United Nations (FAO)and WHO set the Provisional Tolerable Weekly Intake (PTWI) of 4 µg Hg/kg body weight. An approx. 2-5-fold increase of mercury levels in blood and urine in living individuals with dental amalgam as well as a 2-12 fold increase in several body tissues has been observed in deceased individuals with dental amalgam. To measure the effect of mercury amalgam, it is needed to monitor the Hg content of the urine and blood. As the mercury content of the urine is at trace level and the matrix of the samples is exceptionally complicated, a selective pre-concentration method is needed [1-2].

2.EXPERIMENTAL

Natural zeolite, clinoptilolite taken from Semnan deposit in North-west of Iran was firstly purified. 15.0 mg of dithizone and 1.0g of sodium dodecyle sulfate were place in 50mL of 0.1M solution of ammonia and diluted to 100mL with de-ionized water. 1.5g of purified clinoptilolite was ultrasonically washed in 2M nitric acid for 3 minutes and thoroughly rinsed with water. 40mL of de-ionized water was added to the washed zeolite and 10mL of dithizone SDS solution was also added. The suspension was acidified to pH=2 with HCl and shaken for 15 minutes before being transferred to a Millipore filter holder for preparation of the column (1mminner diameter and 9mmhight). Characterization of the adsorbent was performed by Fourier transform infrared spectroscopy (FTIR) using a nicolet Model Impact 400D and thermogravimetric and differential thermogravimetric method using a thermal analyzer Mettler Model TG 50. The synthesized adsorbent was used for pre-concentration of mercury in aqueous solutions and urine real sample. The most popular method of analysis of mercury is cold vapor technique which is based on the absorption of radiation at 253.7nm.The concentration range was adjusted to 0.2-5 Ug/L of mercury. The pre-concentrated samples were analyzed by cold vapor technique using atomic absorption spectrometry. To test the re-usability of the adsorbent, the SDS/dithizon sample was subjected to six adsorption-elution cycles. 4M HNO3 was selected as eluent.


3.RESULT AND DISCUSSION

In the present study, a low cost and environmental friendly solid phase extraction technique was developed based on immobilization of SDS and dithizone onto the zeolite surface. The method can be used for pre-concentration of mercury in the presence of coexisting cation and complicated matrix. The results showed that the method is properly qualified for measurement of mercury in liquid solution and in highly complicated matrix fluid. The detection limit of 0.45µg/L was obtained. It was also deduced from the results that, the urinary mercury concentrations are highly correlated with number of amalgam fillings of the studied peoples.The re-useability of the adsorbent was also examined for six consecutive cycles. It was concluded that the adsorbent kept 89% of its capacity.

Table(1). Reusability of the

adsorbent for Hg pre-concentration Cycles Recovery (%)

1 100.0 2 98.0 3 97.0 4 95.5 5 93.0 6 89.0

REFERENCES 1- A. Moghimi “Selective Pre-concentration and Solid Phase Extraction of Mercury(II) from Natural Water by Silica Gel-loaded (E)-N-(1-Thien-2′-ylethylidene)-1,2-phenylenediamine Phase” Chinese Journal of Chemistry, 2007,Vol. 25, no. 10, 1536–1541, 20 2-Lina Zhang, Xijun Chang, Zheng Hu, Lijun Zhang, Jianping Shi and Ru Gao “Selective solid phase extraction and preconcentration of mercury(II) from environmental and biological samples using nanometer silica functionalized by 2,6-pyridine dicarboxylic acid” Microchimica Acta, 2009, Vol. 168, no. 1-2, 79-85,


synthesized zeolite A from extracted plant’s micro silica and study of cigarette mainstream composition reduction by it

MajidMoradian1*;SamanehAhangar1, FarhadNaghizadeh2, GholamrezaMoradiRobati2

1- Chemistry department, Islamic Azad University, Qaemshahrbranch ,Qaemshahr, Iran;

2- Chemistry department, Tirtash Tobacco Research and Education Center, Behshahr, Iran

1.Introduction Zeolites are importants compounds for removal of harmful compounds in environmental chemistry [1] .cigarette smoke is on of main agents to cancers for human body [2,3] . in this article studied adsorption of cigarette smoke composition by zeolie A(ZA) synthesized from microsilica . microsilicais a compound extract from some plants .Micro silica was extracted from Equisetum arvense plant in North of Iran and purified from Equisetum arvense plant ash in an electric furnace at 1300°C for 4 hours. SEM measurements determined a particle size of micro silica of 1-4micrometer [fig2]. 2. Experimental Sodium silicates synthesized from 10g microsilica and 20gNaOH in 700 C ˚ in electric furnace at 2 hours and extraction by leaching. ZA synthesized by mixing sodium alumina and sodium silicate solutions in 80oc at 48h in Teflon reactor. Then washed with water and ethanol and dry in 150oc .Synthesized zeolite added in 100ml ammonium chloride 0.1M at 72h , then leaching and put in electric furnace at 4h and 450oc . Them washed with water and dry in 100oc .

3. result and dissusion XRD spectrum (diagram1) andXRF (fig1) showed ZA and SEM(fig3) picture showed particle size of ZA to 300-500nm .

Diagram1- XRD spectrum ofsynthesized ZA from microsilica

Fig1- XRF spectrum ofsynthesized ZA from microsilica

Fig2- SEM image of extracted microsilicafrom Equisetum arvense


Fig3- SEM image of synthesized ZA from microsilica

ZA putted in cigarette filter and smoked by smoking machine on standard condition .then was studied adsorption of tar , nicotine , PAHS and heavy metals on ZA by GC/MS (diagram2)and ICP methods . result was showed reduction 50% of tar and nicotine and high adsorption of PAHS compoundsby ZA . Also ICP result showed more than 70% adsorption of As, Cd , Ni , Cr and Co by ZA(fig4). allStepsstudied by SEM and IR .

Diagram2- GC spectrum of adsorption of cigarette smoke compounds on ZA

Fig4-compration of heave metals adsorption on synthesized ZA


Reference :

1- D.W.Breck, zeolite molecular sives , structure , chemistry and use , hohnwiley& sons, Inc., NEWYORK , 1974

2- D.H.Olson and W.M.Meier , Nature 272,437(1978) 3- S.P,Zhdanov, adv.chem.ser.101,20(1971)


Developing a nano-composite hydrogel for arsenic removal from water and wastewater

aratiBiri , Abolfazl M, Taghi ahangiriJShaghayegh *

Chemical engineering department, Faculty of engineering, Arak university,

Arak, Iran

[email protected]

1. Introduction Arsenic(As) is a commonly occurring toxic metal in natural system and is the cause of many diseases. It has been reported that long-term ingestion of As-contaminated drinking water or food causes a series of public health problems (e.g., gastrointestinal, skin, liver, and nerve tissue injuries)[1]. Arsenic is generally present in nature either in organic or inorganic form. The organic form of arsenic is present in sea food, which is less harmful and can be easily discarded by the human body. However, inorganic arsenic, which is mainly present as arsenite (As3+) and arsenate (As5+), is very poisonous for human beings. The World Health Organization (WHO) has limited the safe maximum contamination level (MCL) for arsenic in drinking water to 10 ppb [2]. The contamination of ground water by arsenic usually takes place by the weathering of naturally occurring arsenic-bearing subsurface rocks [3] and the dissolution of minerals from subterranean strata or from an anthropogenic origin such as the leaching of manmade arsenic compounds from smelting of metal ores, agricultural pesticides, desiccants and wood preservatives. Research is developed on improving technologies for arsenic removal in order to achieve concentration limits. Conventional treatment involves coagulation with ferric chloride or aluminum sulphate coagulants, followed by separation of the produced insolubles by settling or by direct filtration through sand beds [8,9]. Other treatment techniques for arsenic removal are reverse osmosis, ion-exchange, lime softening, flotation and adsorption on iron oxides or activated alumina [10–14]. These methods have been reported to be effective mainly for the removal of pentavalent arsenic. Therefore, a pre-oxidation step is usually required, in order to achieve efficient removal trivalent arsenic [11]. The aim of this study is the arsenic removal in our wastewater treatment process. In this study, first first we formulated a nano-clinoptilolite hydrogel as a good candidate for adsorbing the As. Then this formulation is optimized to maximize the As removal. A series of batch tests, were carried out to investigate the adsorption of As(v) on nano-clinoptilolite hydrogel. 2. Experimental

Initially acrylic acid (AAC) beeing titred with NaoH and then N,N'-methylene bis acrylamide added as cross-linker agent to this solution. Also Nano-sized clinoptilolite added to this solution . Then this solution placed at thermo stated water bath with temperature between 800c and 900c and stirred for 30 minutes until the suspension completely formed. After that this suspension added to starch solution which had been placed in the hot water bath. After adding ammonium persulfate solution as initiator, reaction was started. Initial and equilibrium concentration of arsenic investigated with a UV-spectrophotometer.

3. Result and Discussion

Optimal experimental conditions including PH, adsorbent dosage and contact time have been established. Adsorption equilibrium of arsenic ions is occurred at 240 minutes.it was seen that removal of arsenic ions were much faster at low PH than at hight PH. It is clear that percent removal of arsenic decreased by increasing arsenic concentration. Percent removal of adsorbate increased with increasing in adsorbent dosage. Ion exchange (IX) is considered as one of the best available technologies for removing arsenic from drinking water. In Fig.1 we discussed about the effect of mount of acrylic acid on adsorption percent in the


various times and we discovered that at lower mount of acrylic acid,we can have better adsorption percent. In Fig.2 we also discussed about effect of mount of starch on adsorption percent of As in varios time and we found that between various level of Starch that in our research are 2.5 gr ,5gr ,7.5gr ,10gr; the most better

mount of Starch is 5gr.

Fig.1

Fig.2

Reference : [1] Evaluation of a novel hybrid inorganic/organic polymer type material in the Arsenic removal process from drinking water , Carmen M. Iesana,b, Constantin Capat, Florin Rutab, Ion Udrea .

[2] WHO, Guidelines for drinking water quality 1, , 2006.

[3] C.K. Jain, I. Ali, Arsenic: toxicity, speciation and occurrence, Water Res. 34 (2000) 4304–4312.

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Synthesis of modified SBA-15 as catalyst support for atom transfer radical polymerization

of methyl methacrylate

Ebrahim Ahmadi*a, Zahra Mohamadniab, Fatemeh Saghatchia

aPolymer Synthesis Laboratory, Chemistry Department, Zanjan University, P. O. Box 45195-313, Zanjan, Iran

bDepartment of Chemical engineering, Zanjan University, P. O. Box 45195-313, Zanjan, Iran *Corresponding author: 0098 2415152269, 0098 2415152477, [email protected]

1.Introduction

Atom transfer radical polymerization (ATRP), discovered by Matyjaszewski and co-worker [1] and Sawamoto and coworkers [2], has become one of the most useful controlled/‘‘living’’ radical polymerization techniques in polymer science. Generally, in ATRP, organic halide is used as initiator, and transition-metal/ligand complex in its lower oxidation state is used as catalyst. The key point in ATRP is the catalytic system. However, for traditional ATRP, the catalyst residue in the yielding polymer is difficult to be removed after polymerization. Not only does the colored and/or toxic transition-metal residue seriously contaminate the polymer, leading to the product rather hazardous [3], but also the valuable catalyst becomes waste after being used once and causes environmental problems. So, it is urgent to develop new catalytic systems that do not contaminate the polymer products. One approach is to develop sufficiently active catalysts that can provide good control over polymerization at very low concentrations. Another is to design catalysts that can be removed and reused conveniently. Matyjaszewski and co-workers [4, 5] have developed a high active copper-based ATRP catalyst and ARGET (activators regenerated by electron transfer) ATRP catalysts. Alternatively, immobilizing ATRP catalyst on solid support is another good solution, because immobilized catalyst can be easily separated and reused. Therefore, immobilized and recyclable catalytic systems have been and continue to be developed [6]. ATRP utilizes a transition metal, e.g., Cu/SNS complex, as a halogen atom transfer reagent between the dormant and the active polymer chains with the rate constants of activation and deactivation, kact and kdeact, respectively. We previously reported synthesis of different SNS ligands that used in ethylene trimerization [7]. Here we present a study on the ATRP of MMA, using a novel supported catalyst on aminated SBA-15 with Bis-(2-dodecylsulfanyl-ethyl)-amine(SNS) ligand. 2.Experimental

Bis-(2-dodecylsulfanyl-ethyl) amine (SNS) ligand was preparaed according to the producre reported by Mohamadnia et al. [7]. SBA-15 material was synthesized according to the procedure described by Zhao et al. [8]. Amine-functionalized silica was prepared. Then CuBr-SNS/SBA-15-NH2 catalyst was prepared according to the follwing method. 0.128 g of SNS (0.27 mmol) was added to a 20 ml of dry hexane. The resulting colourless homogeneous solution was stirred at room temperature for 5 min under nitrogen. Then 0.039 g of CuBr (0.27 mmol) was added to the reaction flask and the mixture was stirred at room temperature for 15 min under nitrogen. Then 0.125 g of SBA-15-NH2 was added and the mixture was refluxed at 80 °C for 12 hour, under nitrogen to give the corresponding CuBr-SNS/SBA-15-NH2 catalyst in good yield. The solid product was recovered and washed, with 100 ml of diethylether. The light yellow powder was dried under vacuum at room temperature and stored under dry nitrogen.

MMA polymerization: 20 ml MMA was added to 0.128 g (0.27 mmol) Bis-(2-dodecylsulfanyl-ethyl)-amine under stirring. Then 0.039 g (0.27 mmol) CuBr was added to the solution under nitrogen atmosphere at room temperature for 5-15 min. 0.125 g of the aminated silica(SBA-15-NH2) was added to the solution Then 40 µl (0.255 mmol) EBIB initiator was added with refluxing at 90 °C for 90 min. Then the polymer was separated using Alumia column.



Infra-Red spectroscopy was employed to characterize the structure of the ligand. When the ligand reacted with CuBr, the formation of complex was observed, which were isolated as light yellow powders. For this work, UV/Vis spectroscopy was used to determine the oxidation state of the immobilized complexes. As shown in Fig. 1 mole fraction of rr (Syndiotactic), mm (Isotactic) and rm (Atactic) were calculated. According to Fig. 1, syndiotactic, isotactic and atactic percent of PMMA synthesized using CuBr-SNS/SBA-15-NH2 catalyst are 50, 40 and 10 % respectively.

Figure 1. 1HNMR spectrum of PMMA prepared by CuBr-SNS/SBA-15-NH2 in CDCl3.

Conclusions We believe that the reported CuBr-SNS/SBA-15-NH2 catalyst offers an efficient synthesize of poly(methyl methacrylate) with well-controlled molecular weights and narrow molecular weight distributions. Immobilized catalyst can be easily separated and reused. References [1] J.S. Wang, K. Matyjaszewski, J. Am. Chem. Soc. 117 (1995) 5614. [2] M. Kato, M. Kamigaito, M. Sawamoto, T. Higashimura, Macromolecules 28 (1995) 1721. [3] N.V. Tsarevsky, K. Matyjaszewski, J. Polym. Sci. Part A: Polym. Chem. 44 (2006) 5098. [4] H.D. Tang, N. Arulsamy, M. Radosz, Y.Q. Shen, N.V. Tsarevsky, W.A. Braunecker, W. Tang, K. Matyjaszewski, J. Am. Chem. Soc. 128 (2006) 16277. [5] W. Jakubowski, K. Min, K. Matyjaszewski, Macromolecules 39 (2006) 39. [6] Z. Huang, Y. Zhang, H. Li, Y. Liu, Applied Catalysis A: General 332 (2007) 192–199 [7] Z. Mohamadnia, E. Ahmadi, M. Nekoomanesh Haghighi, H. Salehi-Mobarakeh, Catal. Lett. 141 (2011) 474–480. [8] D. Zhao, Q. Huo, J. Feng, B.F. Chmelka, G.D. Stucky, J. Am. Chem. Soc. 120 (1998) 6024.

0 . 00 .00 .50 . 51 . 01 . 01 . 51 . 52 . 02 . 02 . 52 . 53 . 03 . 03 . 53 . 54 . 04 . 04 . 54 . 5

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Preparation and characterization of porphyrin immobilized on hexagonal SBA-15

Ebrahim Ahmadi*, Asemeh Malekzadeh, Zahra Hamdi, Alireza Alizadeh

Polymer Synthesis Laboratory, Chemistry Department, Zanjan University, P. O. Box 45195-313, Zanjan, Iran

*Corresponding author: 0098 2415152269, 0098 2415152477, [email protected]

1.Introduction

The synthesis of structurally complex porphyrins has seen tremendous progress in the last 30 years [1] and is used as catalyst in synthesis of many chemical compounds. However, these porphyrins as homogeneous catalysts have some disadvantages: they may easily be destroyed and inactivated during the course of the reaction, and these expensive catalysts cannot be easily recovered after the reaction for reuse [2]. These drawbacks limit the practical application of porphyrins in both synthetic chemistry and industrial process heavily. These shortcomings can be overcome by chemistry anchoring porphyrins on suitable supports, such as silica, molecular sieves, polymer, polystyrene, Merrifield peptide resins, counter-charged supports, polydimethylsiloxane membranes, xerogels or zeolites, mesoporous SBA-15 [3-4].

Many studies confirm that the anchoring of porphyrins on suitable support materials not only improves catalyst activity, stability, and selectivity of the product because of the support environment, but also enables easy recovery and reuse of the catalyst through simple separation. Among various solid support materials, nanosilica was selected as a carrier because of its high transparency to visible light, wide surface area, and the ability to interact with different functional groups through covalent bonding [5]. In order to achieve a stable binding between porphyrin and support and increasing the porphyrin loading, we have developed a way to synthesize different heterogenized aldehyde and porphyrins. Free base tetraphenylphorphyrin (H2TPP), hetroaldehye (TPHA/SiO2) and silica gel immobilizing porphyrin (CPTTP) were characterized using UV-Visible spectroscopy, FT-IR spectroscopy and CHN analysis. The effects of different kinds of silica gel on porphyrin loading efficiency are evaluated. 2.Experimental

Hexagonal SBA-15 (SBA-15(Hex)) material was synthesized according to the procedure described by Zhao et al.[6] using Pluronic 123 as template. N-(3-triethoxysilylpropyl)-4-formyl benzamide (1) was prepared.Compound 1 with Si(OEt)3 group, was immobilized on synthesized SBA-15(Hex) gel by the following procedure: 1.0 g of silica gel was first calcined in an electrical furnace at 150 C for 3 hour to remove physically absorbed water. Then the silica was added to the solution of ˚aldehyde 1 (2.4 mmol, 0.848 g) in dry hexane (50 ml). The mixture was stirred under reflux (about 73 °C) for 12 h under nitrogen atmosphere. Finally the activated light yellow silica gel (SiO2/TPHA)was filtered, washed with ethanol and then dried at 80 C for more than 12 h. Preparation of heterogenized ˚porphyrin was performed using the Alder-Longo procedure with some changes. The final solid was dried to constant weight under vacuum, and they namely were the functional silica SiO2/CPTPP on which 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (CPTPP) was immobilized. 3.,Results and Discussion

Aldehyde 1, that bears a Si(OEt)3 group, was anchored to support SBA-15(Hex) by controlled hydrolysis of Si-OEt bond and reaction with the free silanols on the surface of the supports.In the next step, heterogenized aldehyde is used for porphyrin synthesis using propionic acid as catalyst as showed in Scheme 1. In the FT-IR spectra of heterogenized porphyrin (CPTPP/SiO2) the characteristic absorption bands of C-H aldehyde groups as described above disappeared completely, and intensity of


absorption bands attributed to aldehyde groups in 1600-1720 cm-1 rang, decreased. The above changes of absorption bands reveal that the Alder's reaction between TPHA/SiO2 and pyrrole as well as benzaldehyde or substituted benzaldehyde in the reaction has occurred, and synchronous synthesis and immobilization of porphyrins on silica were achieved.

Si

O

Si

O

Si

O

Si

O

O

O

OH

O

O

O

O

Si (CH2)3 N

O

CHOH

Silica /TPHA

NH

CHO

+

propionic acid

Si

O

Si

O

Si

O

Si

O

O

O

OH

O

O

O

O

Si (CH2)3 NH

Silica /CPTPP

NHN

NHN

O

Scheme 1. Preparation of porphyrin-doped Silica/TPHA.

The presence of the porphyrin unit on the surface of support was confirmed by IR spectroscopies of the systems. The most important UV–vis characteristics of the CPTPP/SBA-15(Hex) was similar with free porphyrin (CPTPP), showing that the molecules of porphyrin are grafted onto the SiO2. The UV-Vis spectra of TPHA/SiO2 have no characteristic peaks but the spectra of supported porphyrins show the Soret band at 410 nm almost at the same position as the free porphyrin but have much broader bands with lower relative intensity. References [1] The Porphyrins: Structure and Synthesis,D. Dolphin, Ed.; Academic Press: New York, 1979, Vols. 1–2. [2] M. Moghadam, S. Tangestaninejad, V. Mirkhani, I. Mohammadpoorbaltorkb, H. Kargar, Bioorg. Med.Chem. 13 (2005) 2901-2905. [3] M. Ghiaci, F. Molaie, M.E. Sedaghat, N. Dorostkar, Catalysis Communications 11 (2010) 694–699. [4] H.B. Fa, L. Zhao, X.Q. Wang, J.H. Yu, Y.B. Huang, M. Yang, D.J. WangEur. J. Inorg. Chem. (2006) 4355–4361. [5] M.A. Rodrigues, D.B. Tada, M.J. Poloto, S. Brochsztain, M.S.J. Baptista, Non-Cryst. Solids 304 (2002) 116–125. [6] D. Zhao, Q. Huo, J. Feng, B.F. Chmelka, G.D. Stucky, J. Am. Chem. Soc. 120 (1998)6024.


Kineticstudy about oxidation of phenol with H2O2 by using of M-OMS-2/Zeolite Nanocomposite

Mahdavi, Vahid*MojganZendehdelMahboobehHaddadi,

Chemistry Department, Arak University,Arak,38156-88138,Iran *phone number: 09183644690,(E-mail: [email protected])

1. Introduction

Oxidation is one of the most important process steps for producing fine chemicals from petroleum.

Selective oxidation of the hydroxyl group of alcohols is the most common of oxidations.We used

heterogeneous catalysts for this oxidation. Heterogeneous catalysis has several advantages over

homogeneous processes, including simple product isolation as well as catalyst separation and recycling [1].

2. Experimental

In this work, a new nanocomposite by using of OMS-2 and Zeolite-Y was prepared. In this section, when

K-OMS-2 was preparing, Cu, Co and Ni as metallic cations from M (NO3)2 compound as the source of

cations via incorporation method [2]. We added to K-OMS-2 catalyst in a way that the ratio of M/Mn in

final of catalysts was located in 0.05. Then this compound added to synthesized zeolite and we prepared

OMS-2/NaYnanocomposite.

3. Result and discussion

The M-OMS-2/NaYnanocomposite was characterized by several techniques: morphology method(SEM),

spectroscopic methods(FTIR, XRDand TGA) and the nanocomposites was recognized by these

methods.Synthesized nanocomposite used for oxidation of phenol to catechol and hydroquinone with H2O2

as oxidant in acetonitrile as solvent[3]. Consideration of yield shows that following order for M-OMS-

2/Zeolite: Cu-OMS-2/Zeolite > Co-OMS-2/Zeolite > Ni-OMS-2/Zeolite.

Also, the effect of different factors on percent of products in oxidation of phenol such as amount of

catalyst, type of oxidant and solvent and amount of temperature was considered.Results show that the

catalytic activity of prepared nanocomposite in oxidation of phenol have been increased rather than the

reaction without catalyst and the catalytic reaction occurred via a radical mechanism[4].The purpose of

kinetic analysis was to determine the reaction rate constant(K). To determine the reaction order with

respect to phenol, the phenol conversions obtained at different temperature was measured and plotted the

data as –ln(1-X) vs.t.(Fig 2)The value of α that resulted in a liner plot was selected as the phenol reaction

order. This is first order in phenol (α=1).


Refrences:

1- B. Z. Zhan, A. Thompson / Tetrahedron 60 (2004) 2917–2935

2-1-J. Luo, Q. Zhang, A. Huang, S.L. Suib, Micro.Meso.Mater. 35-36(2000) 209

3-M. R. Maurya, J. Salam, J. Titinchi, S. Chand, Journal of Molecular Catalysis A: Chemical, 193,

165,(2003).

4- S. Navalon, M. Alvaro, H. Garcia, Applied Catalysis B: Environmental 99, 1, (2010).

Figure 1.Plot Conversion vs. Figure2. Plot -Ln(l-X) vs.t

The kinetic of oxidation of phenol with excess H2O2 over M-OMS-2/NaY catalysts at several temperature

of 40, 60 and 80 C was investigated. Result show that a pseudo-first order with respect to phenol.

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T=80


Study of nano-composite superabsorbents based on nano-zeolite particles and their application for GhareDagh plant

Marziyeh Darabi* , Taghi Miri , Abolfazl Barati

Chemical Engineering Department , Faculty of Engineering , Arak University , Arak , Iran

*[email protected]

1.Introduction

Today world is faced with many fundamental environmental problems in which desertification are on the main issues. One of the positive managerial acts to deal with this problem is extending the plant cover compatible with the local environment. Therefore, selecting a correct plant types, resilient with the ecosystem conditions and finding necessary nutrient and water resources for their growth is vital. Drought stress is a major constraint for crop production in Iran. Because of shortage of water resources in this area, efficient water use in agriculture is a priority in arid and semi-arid regions where water for irrigation is scarce. Super Absorbent Polymers (SAP) are functional polymeric materials that can absorb large amounts of water including those with good water retention capacity (1) . This water then can be extracted from the gel by suction pressure exerted by plant roots hence use of these materials could be effective for absorbing rain and is a suitable source of water for plant growth. Use of nano zeolite in polymer matrix improves the water absorption and rate of absorption. The aim of the present study is to prepare the best possible hydrogel by evaluating (a) the effect of five different rate of the nano composite superabsorbent , (b) three irrigation regimes (7,15,21 days) and (c) two type of irrigation (water, wastewater) on the growth of NitrariaSchoberi (=GhareDagh which is a salt and drought resistant plant) and soil features.

2.Experimental

N,N’-methylene bis acrylamide (cross-linking agent) was added to acrylic acid (AAC) solution that it is titred with KOH at first. The nano sized clinoptillolite was added to this solution. Then it was placed in a thermo stated water bath and stirred until the suspension was completely formed. After that, this suspension was added to pug solution which it had been placed in hot water bath. Finally, with adding the ammonium per sulfate reaction was started. The resulted nano composite superabsorbent was dried. Dry polymers were mixed with soil and were placed in the plastic plant pots.


Influence of soil type , irrigation regimes and rate of nano composite superabsorbent on wet weight were investigated. It was found that soil type , irrigation regimes and rate of nano composite superabsorbent have significant effect on this study. Nano composite superabsorbent affected the root length , main branch length , number of sub branchs, dry weight and wet weight and soil EC . The results show that nano composite superabsorbent have positive effects on yield and yield components of plant even under drought stress. Since NitrariaSchoberi is a salt and drought resistant plant we can growth this plant in large volume for preventing desertification with little amount of water by use of nano composite superabsorbent.

References

[1] Ping-Sheng Liu, Li Li, Ning-Lin Zhou, Jun Zhang, Shao-Hua Wei, JianShen, Synthesis and Properties of a Poly(acrylic acid)/Montmorillonite Superabsorbent Nanocomposite , 16 July 2006, Published online in Wiley InterScience (www.interscience.wiley.com).


Heterogeneous photodegradation of cephalexin using CuO- NiO/ nanoclinoptilolite

AlirezaNezamzadeh-Ejhieh, NedaAjodanian*

Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan, Islamic Republic of Iran.


1.Introduction: From an environmental engineering point of view, pharmaceuticals including antibiotics are a new

group of man-made chemicals of concern entering the environment at concentrations such thatthe health effects are unknown. Problem that may be created by the presence of antibiotics at low concentration in the environment is the development of antibiotic resistant bacteria [1]. Waste pharmaceutical disposal practices involve a number of conventional techniques, such as sewer and incineration. Despite the widespread utilization of these techniques, they do not help remove drugs from contaminated waters. Waste drugs aredisposed into water through sewer or direct disposal. Such practices could be hazardous and cause serious water contamination. Therefore, two strategies need to be adopted: prevention of disposing waste drugs into sewage system before suitable treatment, and purification of contaminated waters from contaminant drugs. New techniques are thus needed to completely mineralizedrugs disposed in water at large scale. Photo-degradation by solar light could be the ideal technique to use, like other organic contaminants [2,3]. Advanced oxidation process (AOP) based on photo-catalysis has recently been applied for degradation of organic pollutant.When a photon of energy higher or equal to the band-gap energy of semiconductor is absorbed, an electron from the valence band is promoted to the conduction band with simultaneous generation of a hole. Thereby, •OH radicals, superoxide radical anion (O2•−) and its conjugated acid (HO2•) will be produce. These radicals can react with pollutant molecules and disintegrate them into CO2 and H2O [4].

2.Experimental:

First,the purified naturalclinoptilolitewas changed to nano particles bymechanicalmethods. The general procedure for doping of Cu2+and Ni2+ in nano-clinoptilolite described as follows: 1 g of nano-clinoptilolite was added to the 25mLcopper(II) and Nickl(II) nitrate 0.1M and was shaken for 8 h in the polyethylene bottleat room temperature. The solid product was filtered and washed with double-distilled water. Then it was dried atroomtemperature. Finally, the ion-exchanged zeolite was calcined at 450 C in a furnace for 4 h. The obtained samples werereferred to as CuO and NiOnano-clinoptilolite. The proposed catalyst was used in photodegradation of a cephalexine aqueous solution under UV irradiation.

3.Results and Discussion:

To observe the effect of CuO concentration, initial CuO concentration was varied in the range of 0.2–1.0 g/L. Fig. 1 shows the degradation of cephalexin as a function of catalyst mass. Degradation after 240 min irradiation were 60.23 ,62.04, 60.61, 59.22. It is seen that degradation of antibioticse increases with CuO concentration presumably due to increase of •OH production


time(min)

0 50 100 150 200 250 300 350 400

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Fig 1.Effect of CuO concentration on cephalexin

References:

[1] M.V. Walter, J.W. Vennes, Occurrence of multiple-antibiotic resistant enteric bacteria in domestic sewage and oxidative lagoons, Appl. Environ. Microbiol. 50 (1985) 930–933.

[2] A. Nezamzadeh-Ejhieh, Z. Salimi, Heterogeneous photodegradation catalysis of o-phenylenediamine using CuO/X zeolite,Appl. Catal. A :Gen. 390 (2010) 110-118 .

[3] S. EmadElmolla, Malay Chaudhuri, Degradation of amoxicillin, ampicillin and cloxacillin antibiotics in aqueous solution by the UV/ZnOphotocatalyticprocess,J, Hazard. Mater. 173 (2010) 445-449.

[4] S. Hilal, Y. M.Ghazi Al-Nour, AhedZyoud, Muath H. Helal, Iyadsaadededdin, Pristine and supported ZnO-based catalysts for phenazopyridine degradation with direct solar light, solid State Sci.12(2010) 578-586.


Synthesis and characterization of New Poly (amide-imide) Nanocomposites modified

with Silicate Nanoparticles using N-pyromellitimido-L-phenyl alanine

Ehsan Dadfar,a Saeid Aibod b,* a, b Polymer Research Laboratory, Department of Chemistry, Faculty of Science, Islamic Azad University, Arak Branch, Arak, Iran

[email protected]& [email protected]

1. Introduction Polymer-clay nanocomposites typically exhibited mechanical, thermal and gas barrier properties, which are superior to those of the corresponding pure polymers. Unique properties of the nanocomposites are usually observed when the ultra fine silicate layers are homogenously dispersed throughout the polymer matrix at nanoscale. The uniform dispersion of silicate layers is usually desirable for maximum reinforcement of the materials. Due to the incompatibility of hydrophilic layered silicates and hydrophobic polymer matrix, the individual nanolayers are not easily separated and dispersed in many polymers. For this purpose, silicate layers are usually modified with an intercalating agent to obtain organically modified clay prior to use in nanocomposite formation [1-8].

2. Experimental

Two new samples of poly(amide-imide)-montmorillonite reinforced nanocomposites containing N-pyromellitimido-L-phenyl alanine moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) as a source of polymer matrix was synthesized by the direct polycondensation reaction of N-pyromellitimido-L-phenyl alanine with 4,4'-diamino diphenylsulfonein the presence of triphenyl phosphate (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP).

3.Result and Discussion

Morphology and structure of the resulting PA-nanocomposite films 5a and 5b with 5 and 10%silicate particleswere characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposites films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements .

Optical and thermal properties, 4,4'-diamino diphenylsulfone

+ S N H 2H 2 NC a C l2T P PP Y

N M P C CO

N H S N Hn

5

3

4

O

OO

OH

C H 2 p h

N

O

O

N

O

O

C H

p h C H 2

CO

References Please use the following style and formatting 1. Giannelis, E.P.: Polymer layered silicate nanocomposites. Adv. Mater. 8, 29 (1996). 2. Yano, Y., Usuki, A., Kurauchi, T., Kamigato, O.: J. Polym. Sci. Part Polym. Chem. 31, 2493 (1993). 3. Zulfiqar, S., Ahmad, Z., Ishaq, M., Saeed, S., Sarwar, M.I.: J. Mater. Sci. 42, 93 (2007). 4. Sikka, M., Cerini, L.N., Ghosh, S.S., Winey, K.I.: J. Polym. Sci. Part B Polym. Phys. 34, 1443 (1996). 5. Xu, R., Manias, E., Snyder, A.J., Runt, J.: Macromolecules 34, 337 (2001). 6. Kausar, A., Zulfiqar, S., Shabbir, S., Ishaq, M., Sarwar, M.I.: Polym. Bull. 59, 457 (2007). 7. Bibi, N., Sarwar, M.I., Ishaq, M., Ahmad, Z.: Polym. Polym. Compos. 15, 313 (2007) 8. Zulfiqar, S., Sarwar, M.I.: Scr. Mater. 59, 436 (2008).


Synthesis of Analcime via hydrothermal method using TMAOH

Korosh shafiei,a Mansour kazemi moghaddam a , Toraj mohammadi a*, Shahram ghanbari pakdehib

a Research centre for membrane separation process, Faculty of Chemical engineering, Iran University of Science and technology, Narmak, Tehran, Iran.

b Faculty of Chemistry & Chemical Engineering, Malek Ashtar University of Technology, Tehran, Iran

*[email protected]

1. Introductin The Zeolites analcime (Na16(Al16Si32O96)·16H2O) have a compact and complex structure with framework density equal to 18.5T/1000A3. The ANA channels are irregular channels formed by highly distorted 8-rings, and the pore sizes are 1.6×4.2A. Synthesis of compact structure Analcime zeolite has been investigated by researchers using TPAOH organic template, with high silica formulation in gel and a high temperature hydrothermal condition[1-3]. Some of the researchers tried to synthesize this type of zeolite from natural high silica zeolite and natural clinker [4, 5]. M.Tatlier et al. tried to use both microwave and conventional heating methods for synthesis of Analcime with high silica molar ratio gel formulations (160 and 220) and prepared maximum 95.3% crystallinity via conventional heating method at 180 C [1]. In this research, pure Analcime zeolite was successfully synthesized using TMA as an organic template, with low silica formulation in gel and at the mild temperature via hydrothermal method. Synthesis of Analcime zeolite was confirmed by the X-ray diffraction (XRD) method.

2. Experimental For synthesis of Analcime type zeolite powder via hydrothermal method, (Al2O3:SiO2:Na2O:K2O:TMAOH:H2O=1:5:1.3:0.44:3:500) gel formulation was used.

Fumed silica (Aerosil 200, commercial grade) as silica source, Merck grade sodium aluminate powder as aluminum source, Merck grade sodium hydroxide and potassium hydroxide for sodium and potassium sources and Merck grade tetramethylammonium hydroxide as an organic template were supplied for gel preparation.

Conditions of gel preparation and hydrothermal synthesis were as follows:

1. Aluminum source solution was prepared by mixing of sodium aluminate and 30% of calculated water for 1h.

2. Siliceous source was solution prepared by mixing of Aerosil powder, sodium hydroxide, potassium hydroxide, TMAOH organic template and the remained water for 1h.

3. Synthesis gels were prepared by addition of Si source solution to Al source solution with high mixing.

4. Aging time was 24 h.

5. Hydrothermal synthesis conditions were performed in PTFE autoclaves at 145 C for 7 days.

6. Gels were filtered and rinsed by deionized water and dried at 70 C for 24 hours.

3. Results and Discussion Formation of high crystallinity ANA zeolite is confirmed by XRD analysis. 1. XRD analysis XRD analysis is an important tool, which can be used to evaluate structural aspects of a crystalline material. It is especially useful to verify the number of crystalline phases present within a sample. The XRD patterns are presented in Figure 1 related to ANA standard pattern and synthesized sample.


2. Crystallinity of the synthesized power Crystallinity can be calculated via dividing the summation of the intensities related to three maximum peaks by the summation of the intensities of the three maximum peaks summarized in the standard. The measured crystallinity of the synthesized sample was 97% and the calculated Scherrer number was 82 nm.

Figure 1. XRD pattern of the synthesized Analcime zeolite (a) and the standard sample (b) [6].

References

1. Tatlier, M., et al., Microwave vs. conventional synthesis of analcime from clear solutions. Journal of Crystal Growth, 2007. 306(1): p. 146-151.

2. Liu, B.S., D.C. Tang, and C.T. Au, Fabrication of analcime zeolite fibers by hydrothermal synthesis. Microporous and Mesoporous Materials, 2005. 86(1–3): p. 106-111.

3. Ghobarkar, H. and O. Schäf, Effect of temperature on hydrothermal synthesis of analcime and viséite. Materials Science and Engineering: B, 1999. 60(3): p. 163-167.

4. Sandoval, M.V., et al., Synthesis and characterization of zeotype ANA framework by hydrothermal reaction of natural clinker. Fuel, 2009. 88(2): p. 272-281.

5. Joshi, P.N., A. Thangaraj, and V.P. Shiralkar, Studies on zeolite transformation of high-silica gmelinite into analcime. Zeolites, 1991. 11(2): p. 164-168.

6. Higgins, M.M.J.T.a.J.B., Collection of Simulated XRD Powder Patterns for Zeolites. Fifth Revised Edition ed2007: International Zeolite Association. 493.


Effect of some organic additives on synthesis of NaA type zeolite

Koroshshafiei,aMansour kazemimoghaddam a , Torajmohammadia,*Shahramghanbaripakdehi,b aResearch centre for membrane separation process, Faculty of Chemical engineering, Iran

University of Science and technology, Narmak, Tehran, Iran. b Faculty of Chemistry & Chemical Engineering, MalekAshtar University of Technology, Tehran,

Iran *[email protected]

1. Introduction

Many efforts have been performed on controlling shape and size of zeolites crystals for different applications, especially on LTA type[1-7].The effect of different heating sources like microwave and conventional heating, synthesis time, Si/Al ratio and alkalinity have been widely studied. Effect of presence of TMAOH as an organic compound on formation of zeolites crystals like LTA and LTT has been investigated by many researcher [4, 8-11]. In this research, it was tried to investigate on effects of presence of EG, SDS and TMA in crystallization gel on synthesis of LTA zeolite via hydrothermal method. It was found out that crystallizationreaction is accelerated by some of the mentioned additives like SDS, and instead of LTA crystals, faujasit phase is formed.

All of the synthesized crystals were characterized by XRD for confirmation of the synthesized zeolites and PSA analyser was also used to obtain particle size distribution of crystals.

2. Experimental For synthesis of NaA type zeolite powder, two types of gel formulation via hydrothermal method was used in this research.thefirst gel molar ratio, was (Al2O3:SiO2:Na2O:H2O =1:1.7:3:170) and the second one was (Al2O3:SiO2:Na2O:H2O=1:2:3:250). Fumed silica (Aerosil 200, commercial grade) as silica source, sodium aluminate powder as aluminum source and sodium hydroxide for sodium source for gel preparation were used. Different molar ratios of organic compounds were added to prepare gels and the results of hydrothermal synthesis were observed.

All the synthesis conditions were kept constant in powder preparation as follows:

1. Aluminum source solution was prepared by mixing of sodium aluminate and 30% of calculated water for 1h.

2. Siliceous source solution was prepared by mixing of Aerosil powder, sodium hydroxide, the remained water and organic additives for 1h.


4. Aging time for all the prepared gelswerekept 2h.

5. Hydrothermal synthesis conditions were performed in PTFE autoclaves at 70C for 24h for first gel formulation and at 95C for 8 h for the second one.

6. The gels filtered and washed by deionized water and dried at 70C for 24 hours.


The results of XRD analysis for NaA zeolite samples in presence of organic compounds are summarized in Table 1 and XRD graphs are presented in the Figure 1.


Table1. performed tests in presence of organic compounds.

Powder code Additive Additives/

Al2O3 SiO2/Al2O3

Na2O/Al2O3

H2O/Al2O3

Synth temp(C)

Synth time (h)

Formed zeolite

Crystallinity

Scherrer No.

P01 No add. 0 1.7 3 170 70 24 NaA 91% 331 P02 SDS 0.34 1.7 3 170 70 24 NaX 84% 199 P03 TMA 4.76 1.7 3 170 70 24 NaX 84% 100 P04 EG400 0.795 1.7 3 170 70 24 NaX 88% 183 P05 No add. 0 2 3 250 95 8 NaA 80% 190 P06 No add. 0 2 3 250 95 12 NaY 67% 4 P07 No add. 0 2 3 250 95 4 NaA 78% 98 P08 No add. 0 2.3 3 250 95 8 NaY 50% 6 P09 SDS 0.075 2 3 250 95 8 NaY 50% 3 P10 SDS 0.225 2 3 250 95 8 NaX 50% 4 P11 TMA 2.5 2 3 250 95 8 NaY 50% 5 P12 EG400 0.1 2 3 250 95 8 NaA 74% 34 P13 EG400 0.5 2 3 250 95 8 NaA 75% 36

From the results, it can be concluded that using the additives reduces crystallinity and/or shifts to formation of other zeolites.

References

1. Sand, L.B., et al., Large zeolite crystals: their potential growth in space. Zeolites, 1987. 7(5): p. 387-392.

2. Gora, L., Controlled addition of aged mother liquor to zeolite NaA synthesis solutions. Zeolites, 1997. 18(2-3): p. 119-131.

3. van den Berg, A.W.C., et al., Improvement of zeolite NaA nucleation sites on (0 0 1) rutile by means of UV-radiation. Microporous and Mesoporous Materials, 2003. 66(2-3): p. 303-309.

4. Bayati, B., A.A. Babaluo, and R. Karimi, Hydrothermal synthesis of nanostructure NaA zeolite: The effect of synthesis parameters on zeolite seed size and crystallinity. Journal of the European Ceramic Society, 2008. 28(14): p. 2653-2657.

5. Yang, H., et al., Incorporating platinum precursors into a NaA-zeolite synthesis mixture promoting the formation of nanosized zeolite. Microporous and Mesoporous Materials, 2009. 117(1-2): p. 33-40.

6. Li, Y. and W. Yang, Microwave synthesis of zeolite membranes: A review. Journal of Membrane Science, 2008. 316(1-2): p. 3-17.

7. Huang, A. and W. Yang, Enhancement of NaA zeolite membrane properties through organic cation addition. Separation and Purification Technology, 2008. 61(2): p. 175-181.

8. Kim, S.H., et al., Zeolite synthesis in the tetraethylammonium-tetramethylammonium mixed-organic additive system. Microporous and Mesoporous Materials, 2009. 123(1-3): p. 160-168.

9. Cundy, C.S. and P.A. Cox, The hydrothermal synthesis of zeolites: History and development from the earliest days to the present time. Chemical Reviews, 2003. 103(3): p. 663-701.

10. Jihong, Y., Chapter 3 Synthesis of zeolites, in Studies in Surface Science and Catalysis, H.v.B.A.C. Jiří Čejka and S. Ferdi, Editors. 2007, Elsevier. p. 39-103.

11. Qinhua, X. and Y. Aizhen, Hydrothermal synthesis and crystallization of zeolites. Progress in Crystal Growth and Characterization of Materials, 1991. 21(1–4): p. 29-70


Synthesis of zeolite T by using TMAOH

Korosh shafiei,a Mansour kazemi moghaddam a , Toraj mohammadi a,* Shahram ghanbari pakdehi,b

a Research centre for membrane separation process, Faculty of Chemical engineering, Iran University of Science and technology, Narmak, Tehran, Iran.

b Faculty of Chemistry & Chemical Engineering, Malek Ashtar University of Technology, Tehran, Iran

*[email protected]

1.Introduction

Zeolite T or LTT is three dimension intergrowth of OFF/ERI, which has pore sizes of 0.67 nm × 0.68 nm and 0.36 nm × 0.49 nm. This kind of zeolite is a useful microporous material for applying in several chemical processes such as (a) conversion of methanol to C2–C5 olefins; (b) selective cracking of n-paraffins; (c) membrane separation of CO2/CH4 and CO2/N2 gas mixtures and water/organic mixtures[1]. High silica nature of this type of zeolite made it resistant against medium strong acids. Cui, Ying et al. investigated acid stability of zeolite T membranes and used them for dehydration of water/organic liquids [2].Some efforts have been performed for hydrothermal synthesis of this type of zeolite crystals via conventional heating and microwave heating methods [1, 3]. Main gel formulation for hydrothermal synthesis is SiO2:Al2O3:Na2O:K2O:H2O.A. Cichocki et al. [4, 5] and M.Mirfendereski et al. [3] widely investigated specific range of gel formulation, synthesis time and temperature without using organic templates.In this research zeolite T was successfully synthesized at another four different conditions by using of TMAOH as an organic template with reasonable crystallinity. XRD analysis confirmed formation of the synthesized zeolite T powders.

2.Experimental

For synthesis of zeolite T powder via hydrothermal method using conventional heating, 4 different following gel formulations and synthesis conditions were used:

A) Al2O3:SiO2:Na2O:K2O:TMAOH:H2O=1:17:3.194:1.056:3:500 (4 days, 130 C)

B) Al2O3:SiO2:Na2O:K2O:TMAOH:H2O=1:17:3.833:1.267:4:500 (5 days, 145 C)

C) Al2O3:SiO2:Na2O:K2O:TMAOH:H2O=1:23:6.05:2.0:1:500 (8 days, 130 C)

D) Al2O3:SiO2:Na2O:K2O:TMAOH:H2O=1:23:6.915:2.285:2:500 (4 days, 145 C)

Fumed silica (Aerosil 200, commercial grade) as silica source, Merck grade sodium aluminate powder as aluminum source, Merck grade sodium hydroxide and potassium hydroxide for sodium and potassium source respectively, and Merck grade tetramethylammonium hydroxide as organic template for gel preparation were supplied.

Conditions of gel preparation and hydrothermal synthesis were as follows:

1. Aluminum source was solution prepared by mixing of sodium aluminate and 30% of calculated water for 1 h.

2. Siliceous source solution was prepared by mixing of Aerosil powder, sodium hydroxide, potassium hydroxide, TMAOH organic template and remained water for 1 h.


4. Aging time was 24 h.

5. Hydrothermal synthesis was performed differently for each gel formulation.


6. Gels were filtered and rinsed by deionized water and dried at 70 C for 24 h.


Using all four conditions, zeolite T was formed in different crystallinity and Scherrer numbers as Table 1. Figure 1 shows XRD pattern of the synthesized zeolite T.

Table 1. Crystallinity and Scherrer number of our samples Sample Crystallinity % Scherrer number (nm)

A 75% 20 B 85% 56 C 81% 22 D 89% 45

As observed, zeolite T crystals were synthesized with high purity using different gel formulations using TMAOH as template and synthesis conditions.

Figure 1. XRD pattern of samples

References

1. Zhou, R., et al., Synthesis of zeolite T by microwave and conventional heating. Microporous and Mesoporous Materials. 124(1-3): p. 117-122.

2. Cui, Y., H. Kita, and K.-I. Okamoto, Zeolite T membrane: preparation, characterization, pervaporation of water/organic liquid mixtures and acid stability. Journal of Membrane Science, 2004. 236(1-2): p. 17-27.

3. Mirfendereski, M. and T. Mohammadi, Investigation of hydrothermal synthesis parameters on characteristics of T type zeolite crystal structure. Powder Technology, 2011. 206(3): p. 345-352.

4. Cichocki, A. and P. Kościelniak, Experimental designs applied to hydrothermal synthesis of zeolite ERI+OFF (T) in the Na2O–K2O–Al2O3–SiO2–H2O system: Part 3. Mathematical models and geometrical forms of the relationship between product properties and synthesis parameters: an attempt to optimize synthesis conditions. Microporous and Mesoporous Materials, 2000. 41(1-3): p. 241-251.

5. Cichocki, A., et al., Experimental designs applied to hydrothermal synthesis of zeolite ERI + OFF (T) in the Na2O-K2O-Al2O3-SiO2-H2O system. Part 1. Diagnostic study. Zeolites, 1997. 18(1): p. 25-32.


EFFICIENCY EVALUATION OF NaY ZEOLITE AND TiO2/NaY ZEOLITE IN REMOVAL OF METHELENE BLUE DYE FROM AQUEOUS SOLUTIONS

M. Zendehdel, Z. Kalateh,*

Department of Chemistry, Faculty of Science, Arak Uinversity, Arak, Iran

*[email protected]

1. Introduction

In this Study titanium dioxide cluster was incorporated onto NaY zeolite and characterized with X-Ray diffract meter and X-Ray spectroscopy. These composites have many advantages such as high stability and high porosity. The adsorption behavior of methylene blue was investigated for NaY zeolite and TiO2/NaY zeolite. The efficiency of time, pH, temperature and initial concentration of methylene blue (MB) on removal effect of methylene blue was investigated by UV-Vis spectroscopy. The optimum conditions were determined 8h time, basic pH and high initial concentrations of methylene blue and absorbent. With increasing of temperature, the removal of NaY zeolite and TiO2/NaY increased. Results showed that 92% of methylene blue was absorbed by synthesized NaY zeolite and TiO2/NaY zeolite, respectively. Adsorption isotherm as studied by fitting data to Langmuir and Freundlich isotherm models, showed monolayer adsorption and Langmuir equilibrium model to be more relevant. NaY zeolite and TiO2/NaY zeolite were synthesized and charachterized with x-ray diffraction [1, 2].

2.Expetrimental A series of TiO2/zeolite samples were prepared in which the TiO2 incorporated onto zeolite and the efficiency of these nanocomposite materials was found for adsorption of methylene blue. The amount of MB adsorbed was measured spectrometrically (λ661.6 nm) in periodically taken solution samples and again in the same vessel so that the liquid was kept constant. The removal efficiency (RE %) of the dye was calculated by Eq. (1) :

RE (%) = (Co- C/ Co) × 100 (1)

Co and C are the initial and equilibrium concentrations of MB dye solution, respectively.

3.Results and Discussion Fig. 1 shows X-ray diffraction for NaY zeolite and TiO2/zeolite. XRD patterns indicated that the NaY zeolite and TiO2/zeolite are almost similar to the parent. Also no crystalline pattaern was observed for TiO2/zeolite; this might be because of their fine distribution in the lattice. The incorporation of TiO2 had little effect on the crystalline structure of the host zeolite.

Fig 1. X-ray diffraction patterns of NaY zeolite and TiO2/zeolite


NaY zeolite and TiO2/zeolite were used for adsorption of methylene blue and the optimum conditions for the adsorption were determined as 8h contact time, basic pH, because proton ions compete with MB cations for vacant adsorption sites at lower pH and higher pH is favorable for absorption of MB.

Also, high initial concentration and temperature were favorable because of high porosity for NaY zeolite and TiO2/zeolite and endothermic conditions for reaction. At first the absorbance of MB increased with increasing time and then remained constant after 8h. It was also observed that almost 92% and 85% of MB were absorbed by synthesized NaY zeolite and TiO2/zeolite respectively. It seems that TiO2 nanoparticles were anchored on the external surface as well as encapsulated in the cavities of porous zeolite [3]. Hence, with using TiO2/NaY zeolite, the removal efficiency of methylene blue dye decreased triviality. The results of these adsorbents were better in composition with other adsorbents [4]. Finally, the equilibrium removal performance of the composites fitted to langmuire model and has monolayer adsorption.

References [1] D. W. Breck, N. Y. Tonawanda, assigned to Union Corbide, pat. No. 3130007, Pattented Appr., 21,(1964). [2] H. Chen, A. Matsumoto, N. Nishimiya, K. Tsutsumi, Colloides Surf. A, Vol. 157 (1999) 295-305. [3] S. Easwaramoorthi, P. Natarajan, Micropore. Mesopor.Mater., Vol. 117 (2009) 541-550. [4] C. A. P. Almedia, N. A. Debacher, A. J. Downs, L. Cottet, C. A. D. Mello, J. Colloid Interface Sci., Vol. 332 (2009) 46-53.

05

101520253035404550

0 200 400 600 800 1000 1200 1400 1600 1800

RE

(%)

Time (min)

NaY zeoliteNaY zeolite/TiO2


Removal of nickel from aqueous solution by synthesis A-type zeolite

Maryam Ghasemia*, Nahid Ghasemia, Amir Rahimib, Maryam Montazerghaemb a Department of Chemistry, Faculty of Sciences, Azad University of Arak, Arak, Iran

b Department of Chemistry Eng, Isfahan Univercity, Isfahan, Iran * Corresponding author.09187659744, [email protected]

1.Introduction Several industrial wastewater streams may contain heavy metals, including the waste liquids generated by metal finishing or the mineral processing industries[1]. Nickel exceeding its critical level might bring about serious lung and kidney problems aside from gastrointestinal distress, pulmonary fibrosis and skin dermatitis. During the last few years, the common methods availableto remove heavy metal ions from wastewaters are including coagulation, chemical precipitation, ion-exchange, adsorption, and reverse osmosis[2]. Ion exchange is an alternative to the solvent extraction and precipitation methods for removal of toxic metals from different wastes[3]. Zeolites are known excellent adsorbents that can readily adsorb and exchange metal cations with positive charges in their framework[4]. The main aim of the present work is to utilize pure zeolite A samples to remove Ni2+ ions in water.

2.Experimental Sodium metasilicate was used as a silica source and sodium aluminate was used as aluminum source. Heavy metal based solution was prepared using Ni(NO3)2.6H2O. The initial parameter values were: silica source = Sodium metasilicate, Si/Al mole ratio =1.9, H2O/SiO2 mole ratio = 66, Na2O/SiO2 mole ratio = 1.64. Sodium metasilicate and Sodium aluminate were dissolved in separated NaOH solution. These mixtures were stirred for 30 min. A volume of silica mixture was combined with one volume of aluminum mixture and stirred for 30 min, forming a gel. The gel was transferred to an autoclave and heated for 3-4 hr at 99 .The resulting material was centrifuged and washed with water until the pH of the wash liquor decreased from 13 to 10. The material was then dried overnight at 110 C. Batch sorption experiments were conducted with addition of 100 mg of sorbents and 20 ml of Ni2+ solution of initial concentrations (Co) from 50 to 2000 mg l−1 at pH 6 and 25 °C for 14 hr to attain equilibrium conditions. The suspension was then filtered through a Whatman No. 42 to remove the synthesis product. Metal ion concentrations in the filtrate were analyzed using a AA-680 atomic absorption spectrometer.

3.Results and Discussion The synthesis product matched the characteristic peaks of zeolite A at 2 values of 7.2o, 10.3o, 12.6o, 16.2o, 21.8o, 24o, 26.2o, 27.2o, 30o, 30.9o, 31.1o, 32.6o , 33.4o and 34.3o. Adsorption isotherms or capacity studies are of fundamental importance in the design of adsorption systems since they indicate how the metal ions are partitioned between the adsorbent and liquid phases at equilibrium as a function of increasing metal concentration. When an adsorbent and metal ion solution is placed in contact, the concentration of metal ions on the adsorbent will increase until a dynamic equilibrium is reached; at this point, there is a defined distribution of metal ions between the solid and liquid phases. Freundlich, Langmuir and Temkin adsorption isotherm models were applied to study the adsorption capacity of A-type zeplite for the removal of nickel at optimum conditions from aqueous solution. The regression values and correlation coefficients (R2) presented in Table 1 indicate that the adsorption data for Ni(II) removal best fitted the Langmuir adsorption isotherm.


Fig 1. XRD pattern of synthesis product Table 1. The Langmuir, Freundlich and Temkin constants and correlation coefficients of isotherm models

sorbent Langmuir Freundlich Temkin

qm b R2 kf n R2 B A R2

zeolite 100 0.013 0.99 9.44 2.97 0.666 14.04 0.564 0.87

Refrences

[1] Kostas A. Matis, Anastasios I. Zouboulis, George P. Gallios, Torsten Erwe, Christoph Blocher, Chemosphere 55 (2004) 65–72

[2] R.M. Mohamed, Adel A. Ismail, G. Kini, I.A. Ibrahim, B. Koopman, Colloids and Surfaces A: Physicochem. Eng, Aspects 348 (2009) 87–92

[3] Marek Majdan, Stanisław Pikus, Monika Kowalska-Ternes, Agnieszka Gładysz-Płaska, Piotr Staszczuk, Leon Fuks, and Henryk Skrzypek, Journal of Colloid and Interface Science 262 (2003) 321–330

[4] Wei Qiu, Ying Zheng, Chemical Engineering Journal 145 (2009) 483–488

P o s i t i o n [ ° 2 T h e t a ]

1 0 2 0 3 0 4 0 5 0

C o u n t s / s

0

1 0 0 0

2 0 0 0

7.30

9 [°

]

10.2

85 [

°]

12.5

70 [

°]

16.2

27 [

°]

20.5

29 [

°]

21.7

77 [

°]

24.0

98 [

°]

26.2

06 [

°]

27.2

21 [

°]

30.0

53 [

°]

30.9

39 [°

]

32.6

32 [

°]

33.4

78 [

°]

34.2

60 [

°]

35.8

76 [

°]36

.634

[°]

38.0

78 [

°]

40.2

40 [

°]

41.6

35 [

°]42

.268

[°]

42.9

47 [

°]43

.615

[°]

44.2

31 [°

]

47.3

78 [

°]48

.020

[°]

49.8

06 [

°]

52.6

96 [

°]53

.352

[°]

54.2

81 [

°]54

.372

[°]

54.7

31 [

°]


Removal Brilliant Blue from Waste Water by Modified Zeolite

Mohammad Reza Fat’hi* and Morteza Afshoon

Dep. of Chemistry, Faculty of Sciences, Shahid Chamran University, Ahvaz, Iran.

Tel: 09171125801; Fax: +98 6113738502 E-mail: [email protected]; fathiemadabadi @yahoo.com

1.Introduction

Zeolites are microspores, aluminosilicate minerals commonly used as commercial adsorbent. They have a porous structure that can accommodate a wide variety of cations, such as Na+, K+, Ca2+, Mg2+ and others. These positive ions are rather loosely held and can readily be exchanged by others in a contact solution. Zeolites have a negative charge that can be neutralized by exchangeable cations. Thus, zeolites are known as cation adsorbents. To enhance the ability of zeolite to remove anionic dyes, they are modified by cationic surfactants (1). In the past years, natural and modified zeolites have been explored as effective adsorbents for removal of various pollutants such as dyes, metal ions (2-5). In this study, a surfactant modified zeolite (SMZ) was synthesized and applied for removing brilliant blue as an anionic dye.

2.Experimental

Surface modifications

A sample of natural zeolite was used as the starting material in this study. Qualitative X-ray diffraction (XRD) analysis ascertained that the mineralogical composition of zeolite was primarily clinoptilolite (minimum 80%), with trace amounts of feldspar, quartz and pyrite. The cation exchange capacity (CEC) of the starting material was 146 mmol M+/100g measured by 1M, NH4Cl method. Cationic surfactant as methyl tri-octyl ammonium chloride was used for the preparation of SMZ. To obtain SMZ with different loadings, the zeolite powder (0.10, 0.25, 0.50, 0.75 and 1.0 g) was immersed in10 mL acetone containing 0.04 g methyl tri-octyl ammonium chloride (Merck). The suspensions were stirred at 3000 rpm using laboratory mixer at 25º C for 60 min and dried in an oven for 2 h at 90 C.

Adsorption of dye Adsorption was carried out by stirring 25 ml of 20 ppm brilliant blue (Merck) solutions in the presence of 0.2 g of SMZ at room temperature. The adsorption kinetics experiments were carried out in a 50 mL Pyrex glass bottle. The solutions were contacted for 1 h and analyzed spectrophotometrically at λmax of 637 nm. 3.Results and discussion Based on the results, the maximum sorption is in the pH range of 6–9. In subsequent studies, the pH was maintained at approximately 7. In basic solution the concentration of OH− ions would be high, leading to precipitation of the cations as their corresponding hydroxides rather than their adsorption on to the


adsorbent surface. The adsorption capacity was obtained 1.7mmole brilliant blue per each gram of modified clinoptilolite. The effect of foreign ions was studied. A fixed amount of brilliant blue was taken with different amounts of foreign ions, and the recommended procedure was followed. The tolerance limit was as the amount of each ion that require for causing ±5% error in the determination of brilliant blue. References

[1] R.S. Bowman, Microporous Mesoporous Materials, 60(2003) 43.

[2] L.R. Weatherly, N.D. Miladinovic, Water Research, 38(2004)4305–4312.

[3] S.K. Alpat, O. Ozbayrak, S. Alpat, H. Akcay, Journal of Hazardous Materials, 151(2008) 213–220.

[4] S. Wang, T. Terdkiatburana, M.O. Tadé, Separation and Purification Technology, 62 (2008)64–70.

[5] B. Armagan, O. Ozdemir, M. Turan, M.S. Celik, Journal of Chemical Technology and Biotechnology, 78 (2003)725–732.


Use of Natural Zeolite in Sustainable Agriculture

Ashraf Najafia & M.R. Davarib*

a M.Sc. of Agronomy, Arak, Iran b Ph.D. of Agroecology, Arak, Iran

* Corresponding Author. Phone Number: +988612225931, Email address: [email protected]

1.Introduction

Sustainable agriculture is a productive, competitive and efficient way to produce safe agricultural products, while at the same time protecting and improving the natural environment and social/economic conditions of local communities. An increased expectation can be environmentally sound and maintainable farming, in our homeland opposite with the modern cultivation and agricultural activities. Introduction of these methods is a requirement without the application of the agrochemical products or with its great reduction in face of the soil fertility and plant nutrition. The aim is to avoid the environmental loads of pollutants and to keep in mind the sustainablity. There is great necessity nowadays for applications of natural susbstances like the zeolite in the agriculture. Identification of zeolite as a mineral goes back to 1765, when a Swedish mineralogist, Fredrich Cronstet, began collecting some well-formed crystals from a copper mine in Sweden. Zeolites have many important tasks such as ion exchange, filtering, odour removal, chemical sieve, water softener and gas absorption. Therefore, a part of agriculture, numerous examples of their application are stabilization of soil, building materials and fixation of phosphates.

2.result and disssusion.

Structure of Zeolite

Zeolites are composed pf pores and corner-sharing aluminosilicate (Alo4 and SiO4) tetrahedrons, joined into 3-dimensional frameworks. Zeolite has large vacant spaces or cages within and resemble honeycomb or cage like structures. The presence of aluminum results in a negative charge, which is balanced by positively charged cations.

Production of Zeolites in the world

According to reports of 2010, the total consumption of zeolites was 4 million tons. The use of natural zeolites has been continuously increasing over last years. Such countries as Cuba, USA, Russia, Japan, Italy, South Africa and Bulgaria have important resources of these minerals and production potentials.

Application of Zeolite in plant nutrition

Zeolite in agriculture improves efficiency of used fertilizers, thus promotes better plant growth and consequently enhances the yield. Zeolites are used successfully in the cultivation of a wide variety of crops including cereals, vegetables and legumes. Zeolites added to fertilizers help to retain nutrients and, therefore, improving the long term soil quality by enhancing its absorption ability. It concerns the most important plant nutrients such as nitrogen (N) and potassium (K), and also calcium, magnesium and micro-elements. Therefore an application of zeolites will enhance the plant growth and development by reducing the loss of nutrients. Mokhtarnia and Siadat (2011) reported that corn yield in integrated treatment of manure; zeolite and chemical fertilizer increased compared with chemical, organic and even integrated system without zeolite.


Gas absorption

Natural zeolites can absorb CO, CO2, SO2, H2S, NH3, HCHO, Ar, O2, N2, H2O, He, H2, Kr, Xe, CH3OH and many other gases and can thus be used to collect them or control odours in composting and vermicomposting. Additionally, food crops growing in soil containing high amounts of Pb, Cd, and Cu can be protected by the absorption of zeolites. Also, research showed that S90 uptake by plants was significantly reduced.

Water absorption

Zeolites may hold water up to 60% of their weight due to a high prosity of the crystalline structure. Zeolites assure a permanent water reservoir, providing prolonged moisture during dry periods; they also promote a rapid re-wetting and improve the lateral spread of water into the rooz zone during irrigation. Furtheremore, high absorption capacity make zeolites a carrier of agricultural pesticides. Zeolite may act as a wicking material under certain conditions and draw water through capillary action from a shallow groundwater table up to the root zone of newly established plants allowing water to move to the plant’s root and thus reduce dependence on surface water or precipitation.

Ion exchange

Zeolite with a negative charge provides a ideal trap for positive cations such as sodium, potassium and calcium, and positively charged groups such as water and ammonia. Therefore, alkali and soil alkali metallic cations are attracted in the same way and water can be absorbed by zeolites. Iranian zeolite clinoptiolite is capable of exchanging up to 11 mg g-1 ammonium. Therefore it can be concluded that natural zeolite is a suitable cation-exchanger and can be an appropriate anion-exchanger under surfactant bilayer configuration (Malekian et al., 2011)

Soil amendment

Unlike other soil amendments zeolite does not break down over time but remains in the soil to improve nutrient retention. Therefore, its addition to soil will significantly reduce water and fertilizer costs by retaining beneficial nutrients in the root zone. Soil amendment with zeolite could effectively ameliorate salinity stress and improve nutrient balance in a sandy soil (Al-Busaidi et al., 2008). for agriculture applications is due to its relatively high absorption rate, cation exchange, catalysis and dehydration capacities. Zeolites are, therefore, used to promote better plant growth by improving the value of fertilizers. They retain valuable nitrogen and improve the quality of the resulting manures and sludge and can also be used as a molecular sieve or filter medium. Zeolite also acts as a filter to removal of heavy metals by adsorbing them due to the cation exchange capacity.

References

Al-Busaidi, A., T. Yamamoto, M. lnoue, A.E. Eneji, Y. Mori and M. Irshad. 2008. Effects of zeolite on soil nutrients and growth of barely following irrigation with saline water. The 3rd international conference on water resources and arid environments. 279-283.

Malekian, R., J. Abedi-Koupai, S.S. Eslamian, S.F. Mousavi, K.C. Abbaspour and M. Afyuni, 2011. Ion-exchange process for ammonium removal and release using natural Iranian zeolite. App. Clay Sci., 51: 323-329.

Mokhtarnia, Sh and S.A. Siadat. 2011. The study of using zeolite integrated with ship manure before composting in reducing the consumption of chemical fertilizer in corn cultivation in light textural soils in Khuzestan, Iran. American Journal of Scientific Research. 32: 90-97.


Surface complexation modeling of Pb and Cd onto 13X and Na-Y synthesized zeolites

Lotfollah Karimzadeh

TU Bergakademie Freiberg-Department for Hydrogeology- Gustav-Zeuner-Str. 12 09599 Freiberg. Germany.

[email protected] Abstract

Surface complexation models as an equilibrium-based approach have been used vastly to describe and predict cation and anion sorption reaction on mineral phase surface sites and have been quantitatively and qualitatively developed rapidly during the past decades. The accuracy of such a model is highly dependent on the ability to predict the required parameters such as surface sites (density), term of electrostatics and protonation mechanisms. In this work the generalized two-layer model was applied to explain the sorption of Pb and Cd onto two synthesized zeolites (13X and Na-Y) and to estimate the sorption parameters. Batch sorption and titration experiments were conducted in laboratory at pH 4 to 9 under normal laboratory conditions. The aqueous speciation of metals was calculated by the thermodynamic modeling program PHREEQC 2.16 (Parkhurst and Appelo, 1995) using the llnl.dat database at pCO2=10-3.35. The non-linear least squares parameter estimation program PEST 11.8 (Doherty, 2004) coupled with PHREEQC 2.16 (Bachmaf and Merkel, 2011) used successfully to determine the stability constants of surface complexation reactions with the dominant aqueous species. The predicted sorption in the model showed good agreement with the observational data from the laboratory experiments (error < 7%).


Heterogeneous Photodegradation of Mixture of MethylenBlue/Bromophenole Blue using

CuO/nano-clinoptilolite

AlirezaNezamzadeh-Ejhieh*, HamidrezaZabihi-Mobarakeh

Department of Chemistry, Shahreza branch, Islamic Azad University,P.O Box 311-86145,Shahreza,Isfahan,Iran


[email protected]

Abstract:

In this study, the natural nano-clinoptilolite zeolite has been used for

increasesphotocatalyticactivity CuO in photodegradation of mixture of dyes.The

photocatalytic activity of CuO particles loaded inside the channels of nano-clinoptilolite

zeolite was studied in photodegradation of mixture of methylen blue and bromophenol blue

under UV irradiation[1]. The degradation efficiencies of dyes mixture were measured in

different times. The nanoclinoptilolitewas prepared bymechanical process in the mill at 6

h.Photocatalystswere prepared by ion exchanging process of nano-clinoptilolite with

copper(II) nitrate aqueous solutions (0.1, 0.2, 0.3, 0.5 M) for 24 h followed by drying and

calcinations at 450 °C for 12 h and it was characterized by FT-IR and X-ray diffraction.The

effect of various experimental variables on the photo-degradation performance of the process

was evaluated by examining catalyst dosage, catalyst concentration, initial dye concentration

and pH of the dye solution. The optimum condition for the degradation of the dyes was at

concentration 7 ppm, pH 5.9, catalyst dose 0.2g/L andcontact time 180 minutes. The changes

of dyes concentration were determined by UV–Visible double beam spectrophotometer at

λmax 664 nm for the MB and 595 nm for the BPB.The degradation of 61% for MB and of 32%

for BPB was obtained after 180 minutes.

Kyewords: Zeolite, Nano-clinoptilolite, Photodegradation, Dyes

References:

[1] AlirezaNezamzadeh-Ejhieh, ShohrehHushmandrad, Solar photodecolorization of methylene blue by CuO/X zeolite as a heterogeneous catalyst, Appl.Catal. A: Gen. 388 (2010) 149–159.


Sorption of phenol using partial template-containing MCM-41

EdrisSedighi, Mohammad A.Zanjanchi*

Department of Chemistry, Faculty of Science, University ofGuilan, Rasht, 41335-1914, Iran

*Corresponding author. Phone number 09111311527, Fax number 01313226643, E-mail address [email protected]

1. Introduction

Porous materials have regular and continuous skeletons and voids with large surface areas. According

to the definition of IUPAC, porous materials can be divided into microporous,mesoporous and

macroporousgroups.The presence of micro- or mesopore channelsallows for molecules to penetrate

into the large internal space consisting of active sites. In spite of the considerable efforts that have

been made toward making larger and regular pore systems, ordered mesoporous materials still

remained indefinableuntil the discovery of MCM-41 in 1992. The MCM-41 materials

establishhexagonal mesostructures with uniform pore size in the range of 30-100 Å. MCM-41 can be

easily synthesized under the room temperature conditions in the presence of alkyltrimethylammonium

surfactant cations as structure-directing template [1].Elimination of the templates from thepores of

MCM-41can create huge pore space andsurface area. There areseveral ways to remove template

includingcalcination, ion-exchange and solvent extraction. However, keeping the template molecules

(or part of them) inside of the channels of MCM-41 may also provide a suitable sorbent for organic

compounds [2]. In the present work, we prepared MCM-41 and then extracted parts of its template by

treating it in ethanol under ultrasound waves. We examined the potential of the prepared adsorbents

for sorption of phenol.

2.Experimental

Cetyltrimethylammonium bromide (CTAB), which is the template used for preparation of MCM-41,

was detetermined by UV-Vis spectrophotometric technique after it was extracted into ethanolic

solution. MethylOrange was used as reagent to interact with CTAB to produce associated ion-pair

compound [3]. The ion-pair was then extracted into chloroform which settles as a lower layer in the

separator funnel. The extraction was performed at a constanttemperature of25ºCand at different

contact times. The amount of CTABremoved out from the pores of MCM-41 was estimated following

the spectrophotometric determination.


The amount of the removal of CTAB from the pores of the synthesized MCM-41was measured using

methyl orange as an ion-pair agent.


Preliminary studies showed that treating the as-synthesized MCM-41 in ethanol which was exposed to

ultrasound waves for various time will lead to extraction of different amount of the surfactant out of

the meso-channels of MCM-41. Table 1 shows the amount of CTAB remained in the pores of MCM-

41 at different sonication time according to the data obtained from methyl orange measurements.

According to the obtained data longer time of the treatment leads to less amount of CTAB in the

structure. These samples were used for examining the adsorption of phenol. Different pH was tried to

find out the highest amount of adsorption. Ourinspection showed that a relatively basic pH such as 9

is suitable for adsorbing phenol by the partial template-containing MCM-41. AtthispHthe phenolate

negative species are prominent and both hydrophobic and electrostatic interactions are involved in

phenol adsorption onto the mesoporous sample. Table 2 shows that by eliminating some of the CTAB

molecules out of MCM-41 capacity of the mesoporous MCM-41is promoted for adsorption of phenol.

However, longer treatment which cause more elimination of the CTAB molecules do not alter this

significantly. We conclude that little space created by eliminating some of the CTAB is sufficient for

efficient removal of phenol and eliminating higher amount of CTAB does not improve the adsorption

capacity of the adsorbent.

Table 1Amount ofCTAB residuals in MCM-41Table 2Removal ofPhenol by the treatedMCM-41

References

[1] M.A. Zanjanchi, Sh. Asgari, Solid State Ionics.171 (2004 ) 277.

[2] L. Huang , Q. Huang, H. Xiao, M. Eić, Micropor.Mesopor.Mater.98 (2007) 330.

[3] G.V. Scott, Anal. Chem.40 (1968) 768.

%Removal % CTAB Sample

39.24 100 MCM-41

55.51 69.5 MCM-41(US1)

57.01 55.2 MCM-41(US3)

58.93 43.3 MCM-41(US5)

59.83 25.0 MCM-41(US7) 63.59 13.1 MCM-41(US10)

% CTAB residual

CTAB conc (molL-1)

Treatment time (min)

69.5 4.01×10-6 1

55.2 5.90×10-6 3

43.3 7.46×10-6 5

25.0 9.87×10-6 7

13.1 1.14×10-5 10


Preparation and characterization of filled matrix membranes of poly(vinyl alcohol) incorporated with NaX zeolites

Maryam Heydari,a, *Ahmad Mohebb, aDepartment of Chemical Engineering, Isfahan University of Technology, Isfahan 8415683111,

Iran b Department of Chemical Engineering, Isfahan University of Technology, Isfahan 8415683111,

Iran *Corresponding author. 09134128078,[email protected]

1.Introduction

Mixed matrix membranes are hetrogeneous membranes consisting of inorganic fillers embeded in a polymeric matrix. Among the various membranes, zeolite-filled membranes are now being widely used in view of their better advantages over the plain conventional polymeric membranes[1]. Such filled membranes are chemicaly and thermally more stable and exhibit better potential than pristine membrane in separating liquids by adsorptive and moleculare sieving effects, because the zeolite pores have moleculare size that can affect the separation more effectively[2] Zeolites have a high mechnicalstrengh , good thermal and chemical stability and the membranes incorporated with these fillers can be used over a wide range of operating conditions[3].Recently , some authors have published the preparation results of mixed matrix membranes using zeolite as a filler to investigate of the mechanical and thermal stability of these membrane in compared to the plain polymeric membranes[4].In the present paper, the NaXzolite-filled PVA membranes were preparaed. The effects of filling on the structure and the mechanical and thermal stability of PVA/NaX membranes were investigated.

2.Experimental

A 10 wt% homogeneous PVA solution was preparedand different amounts of zeolite NaX ,i.e. 10, 20 and 30wt% (based on the weighted of PVA) separately was added to PVA solution and stirred for 24 hr at 50oC to achieve a homogeneous solution. After that a specific amount of fumaric acid (5wt% polymer) as a crosslinking agent was added to previously prepared PVA solution and the mixture was stirred at 50oC overnight. Then the the degassed solution was casted on a flat glass plate by using a casting knife. The casted film was kept at room temperature in a dust free atmosphere for 24 hr Then, the dried membrane was peeled off from the glass plate surface and heated in a vacuum oven at 150oC for 1 hr .The resultingself-supported membranes were designated as PVA-10 (for 10wt% of zeolite) ,PVA-20 (for 20wt% zeolite) and PVA-30 ( for 30wt%), respectively The membrane were characterized through SEM, FT-IR, XRD and TGA as well as tensile test .


The FT-IR spectra of plain PVA and NaX filled PVA membranes are shown in Fig.1 . A characteristic strong and broad band is appeared around 3421cm-1correspond to streching vibration of O-H in PVA membrane. The peak observed at 2918cm-1 attributed to C-H streching and bands at 1441cm-1 and 1081cm-1 related to C-O single band. For mixed matrix membrane in addition to these peak exhibit extra two peaks around 1000cm-1 and 800cm-1 is assigned to Si-O and Al-O vibration. The thermogravometric analysis used to investigate the thermal stability of plain and mixed matrix membrane and it’s result displayed in Fig. 2.According to Fig .2 . the decomposition for all of the membranes take place in three stage. The first decomposition stage is observed between 40oC to 250oC for plain PVA and 40oC to 299oC for mixed matrix membranes. The weight loss is about 5wt% for all of the membranes in this stage that attributes to elimination of bound water molecules in membranes. The second stage is between 250oC to432oC and 299oC to 460oC for plain and mixed matrix membrane respectivily. The third decomposition stage starts above 432oC for plain PVA and 460oC for


mixed matrix membrane and follow to 700oC. The TGA plots of mixed matrix membranes have a similar trendecy to plain PVA except for a weight residue at higher temperature. It indicates that mixed matrix membranes have better thermal stability than that plain PVA.The X-ray diffraction pattern of PVA and zeolite incorporated PVA membranes are presented in Fig.3. The broad peak around at 20o of 2 is observed for all of the membranes indicating that PVA is a semicrystal polymer but the intensity of this peak decrease with increasing the zeolite content in PVA membranes. It demonestrates that the zeolite avoid to formation of crystalline regions. It atributes to strong intraction between zeolite and PVA hydroxyl groups. Therefore amorphous region are more than crystalline regions in the mixed matrix membranes.Fig.4 .showes the cross section morphology of PVA-0,PVA-10 and PVA-30. As observed for all the membranes zeolite particles distributed uniformly in the polymer cross section.Themembrane ‘s preparation and casting method have important influence on the distribution of zeolite in the PVA matrix. Fig. 3d indicates that no defects are found at the interface of zeolite and PVA. Therefore NaX zeolites have excellent adhesion with polymer matrix because of hydrophilic-hydrophilic interaction between polymer and NaX zeolites. In order to study the effect of incorporation zeolites on mechanical stability of membranes tensiltestrengh at break and young’s modulus were measured and it’s result reported in Table.1

Fig.1 FTIRspectra of for different membranes,(a) PVA-0, (b) PVA-10, (c) PVA-20,and (d)PVA-30

Fig.2 The TGA plots of (a) PVA-0, (b) PVA-10, (c) PVA-20,and (d)PVA-30

Fig.3 X-ray diffraction patterns for different membranes

Fig.4 Cross-sectional scanning electron micrograph of (a)PVA-10,(b)PVA-20,(c) PVA-30 and (d) enlarge cross-sections of PVA-30

Table 2

Tensile strengh and young’s modulus of plain PVA and MMMs Membrane type Tensile strength (N/mm2) Young’s modulus (MPa)

PVA-0 58.6 2747

PVA-10 66.3 4192

PVA-20 75.8 5530

PVA-30 84.1 7674

Refrences [1]S.D. Bhat, T.M. Aminabhavi,Separation and Purification Technology,51(2006)85 [2] M.B. Patil, T.M. Aminabhavi, Separation and Purification Technology,54(2007)34 [3]H.Dogan, N.D. Hilmioglu, Vacuum,84(2010)1123 [4]Sh.B. Teli,M. Calle, N. Li, Journal of Membrane Science,371(2011)171

400900140 0190 0240 0290034003900

W av en u m b ers (cm -1)

Tran

smitt

ance

(%)

0

20

40

60

80

100

0 100 200 300 400 500 600 700

T emp erature (oC)

Wei

ght l

oss(

wt.%

)

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

0 1 0 2 0 3 0 4 02 t h e ta (d e g r e e )

Inte

nsity

(a.u

.)

(a)

(b)

(c) (d)


Immobilization of complex cu of 1-Salicylideneaminooxy,2(-2-hydroxy-

isophthaldehideneaminooxy)ethan on MCM-41 Goldasteh Zarei*1, F. Adhamei1, F.Salehi1

1Chemistry Department,Faculty of Science,IslamicAzadUniversityShahr-e-Rey Branch,Tehran,Iran, (Email:[email protected])

1.Introduction Salen and its derivatives are well-knownchelating ligands in coordination chemistry.[1–3] During the past few decades, metallosalencomplexes have been of considerable current interest due to their ubiquitous use in a variety ofcatalytic chemical transformations. Examples where salen complexes offer both high eactivity andselectivity include epoxidation of olefins, asymmetric ring-opening of epoxides, olefinaziridination, olefin cyclopropanation and formation of cyclic and linear polycarbonates.[4] Salencan be used to obtain non‐linear optical materials,[5] biological systems,[6] interesting magneticproperties[7] and building blocks for cyclic supermolecular structures[8].A general strategy for converting a homogeneous process into a heterogeneous one is to anchorthe soluble catalyst onto large surface area inorganic supports .The main advantages ofheterogenization are the easy separation of the catalyst from the reaction mixture, allowing thepossibility to recover and reuse the catalyst, and the possibility of continuousflow operation. Thecommon problem of this methodology is leaching of the active sites from the solid surface into thesolutions, when applied to liquid‐phase reactions. However, this can be avoided or minimized bycovalently anchoring the active sites onto the inorganic solid supports. As a support, MCM 41 silicahave been widely used since the performance of this material in catalysis is directly related to astructure possessing hexagonally packed arrays of one dimensional cylindrical pores, with porediameters ranging between 20 and 100A °, large surface areas of up to 1500m2 g_1 and porevolumes up to 1.3 cm3 g_1. In this study, we were synthesized the chiral salen complexes and immobilized onto the MCM-41. 2.Experimental The synthesis of MCM-41 Coated membrane composites was performed using a silicasol contains surfactant in ethanol solvent. To prepare the prehydrolyzed inorganic precursor solution,tetraethoxyorthosilane (TEOS) in EtOH was hydrolyzed in aqueous HClsolution. Themolar ratio was 1.0 TEOS: 0.2 CTABr : 0.14 HCl : 36.5 Ethanol : 8.0 H2o1,2-Bis(phthalimidooxy) ethane(2) 1,2 -Bis(phthalimidooxy) ethane was prepared according to amodified procedure of Bauer and suresh in which 1 equiv of 1,2 – dibromoethane was alkylatedwith 2 equiv N-hydroxyphthalimide in dimethylformamide containing 6 equiv of triethylamine toogive an 84% yield of the desired product as white needles . The solid could be recrystallized fomehot dimethylformamide but was usually used without further purification. Thenwas synthesized Complex of Cu as Scheme 1.

H2N O O NH2ETOH,Reflux

OH

O

2HN O O N OH

OETOH,Reflux

N O O N

HO

HO

OH

O

OO

O

N O O N

OETOH,Reflux

Cu(OA )2 Cu

Schema1

Then,the chiral salencomplexe of Cu wasimmobilized onto the MCM-41 bymethod according to the procedure as shown in scheme 2.

OH OH OH

(CH3O)3Si NH2

+ Toluene

RefluxO O O

Si

H2N

MCM-41

MCM-41

O

O

N O O N

OCu

ETOH,Reflux

O

N O O N

OCu

O O O

Si

N

MCM-41 Scheme2


3.Results and discussion This work reports the covalent attachment of new salen-type bisoxime complex of Cu on MCM‐41,by the new grafting method using 3‐aminopropyltrimethoxy silane. Additional information wasobtained by powder X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), CHNmicroanalysis, FTIR spectroscopy. IR(CHCl3)3325,3000,2925,1585,1188,1050cm-1,1H NMR(CDCl3) 3.71(s,4H,5.31(br s,4H,exchanged with D2O);13C NMR (CDCl3) 73.7;mass spectrum, m/e(relative intensity)93(M+,20),66(59),65(23),64(10),63(13). References [1]Hall D,Waters TN,J,Chem.Soc.1960;2644. [2]Reglinskij,Morriss,StevensonDE.Polyhedron 2002;21:2167. [3]GarnovskiAD,NivorozhkinAL,Minki VI. Coord.Chem.Rev.1993;1:126. [4]CanaliL,Sherrington DC.Chem.Soc.rev.1999;28:85. [5]LacroixPG.Eur.J. Inorg. Chem.2001;14:339. [6]TisatoJ ,RefoscoF,Bandoli f. Coord . Chem.Rev.1994;135:325. [7]CostesJP ,Dahan F ,Dupuis A. Inorg. Chem.2000;39:165. [8]Sun SS,SternCL,NguyenST,Hupp JT. J. Am. Chem.Soc.2004;126:6314


Characterization of a natural zeolite from Hesarbon area, Damavand, Iran

MonirehKhosraviNasaba*, TaymorEslamkisha, HeshmatollahGhassedb

a Department of Mining & Metallurgy Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran

bKavoshKansar engineering compony,Tehran,1435673615,Iran *Corresponding author. Tel.: +98 912 2809683; E-mail address: [email protected]

1. Introduction

Zeolite minerals are known as natural sedimentary or natural occurring zeolites [1]. They are mainly composed of aluminosilicates with a threedimensional framework structure bearing AlO4 and SiO4tetrahedra. These are linked to each other by sharing all of the oxygen to form interconnected cages and channels containing mobile water molecules and alkali (sodium, potassium, lithium, and caesium) and/ or alkaline earth (calcium, strontium, barium, and magnesium) cations [2]. Today human have known more than 48 natural zeolite species in the world. These zeolites are differed by their various chemical composition, structure and properties. Zeolites are particular materials and due to their specific properties they are applied in various industries. The properties of zeolites such as their thermal stability, sorption, cation exchange capacity, catalytic activity and selectivity are depending on the chemical composition and structure of a zeolite. The Si/Al ratio, the type and number of the extra framework cations, their specific surface area, pore volume and etc., are directly related to their chemical composition and structur [3]. 2. Experimental

Samples of zeolite were collected from the Hesarbon mine. Mani physical properties are summarized in table 2.After sampling from the site, samples were ground, homogenized and sieved. The samples between 0.5 to 2 mm were selected. Prior to all analyses the samples had been washed with deionized water to remove dust and other soluble impurities.

Table 1Main physical properties of the Hesarbon zeolite.

Color White – pale greenish blue Specific gravity (g cm-1) 2 - 2.5 Particle size (mm) 0.5 - 2 Cation exchange capacity (meq g-1) 1.67

3. Results and discussion

XRD analysis showed that major phases were clinoptilolite and quartz, and the minor phases were cristobalite,montmorilonite, albite, calsite and gypsum. In Fig. 1, a typical XRD diagram of the Hesarbon zeolite is reported. The presence of amorphous materials that are inherent in the zeolite is indicated in the XRD diagram by the broad hump registered between 20 and 30 2θ [4]. The (020) and (004) reflections are characteristic of clinoptilolite.


Fig. 1. XRD diagram of representative zeolite sample from Scaloma:

The results from the XRF analysis of the Hesarbon zeolite samples are presented in Table 2. The overall nSi/ nAl ratio is 5.55. The high overall nSi/nAl ratio can be attributed to the existence of mordenite and of a non-quantified proportion of cristobalite in the samples.

Table 2 XRF analysis of the Hesarbon zeolite Constituent(% w/w) SiO2 Al2O3 K2O CaO Na2O MgO Fe2O3 L.O.I

Average concentration

66.3 10.53 1.69 3.04 2.93 1.94 2.65 9.6

The electron scanning of the samples, apart from confirming the results from the XRF and XRD analyses (through semi-quantitative element analyses on large surfaces and/or directly on the surface of crystals), provided some interesting photos.Photomicrographs of the Ch-zeolite sample, obtained by SEM, are shown in Fig. 2.

Fig. 2. Typical topographic image for the original Hesarbon zeolite byScanning electron photomicrographs (SEM). The adsorbed water of zeolites is driven off by heating at a temperature <450 _C, without the structure being decomposed [5]. A typical TG/DTG curve of the Hesarbon zeolite is shown in Fig. 3. The TG curves showed a continuous weight loss during heating up to 600°C, due to the loss of water. The weight loss due to the desorption of physisorbed water is In the temperature range from 25 to 100 °C. In the temperature range from 100 to 200 °C, the rapid weight loss is documented by the steep slope of the TG curve as it is attributed to the loss of loosely bonded water. In the temperature range from 200 to 300 °C, the weight loss is less, and it is indicated by the slight slope of the TG curve. In this stage, the water loss follows a slower rate. In the temperature range from 300 to 400 °C, the rate of water loss is even slower; and In the temperature range from 400 to 500 °C, the slope of the TG curve is even lighter. In the temperature range from 500 to 600 °C, the rest of the water is gradually removed


Fig.3. TG/DTG curves of Hesarbon zeolite.

The FTIR spectra can be very useful in obtaining information about the structure, channel size and the cation substitution (Si4+ by Al3+) in the tetrahedral sites of zeolite minerals [6]. Fig.4 shows the FTIR spectrum of the Hesarbon natural zeolite. The strongest T–O stretching vibration appears at 1058.5 cm-1. This band is significant for the estimation of aluminum content in the crystalline framework. The exact position of this band depends on the nSi/nAl ratio and is considered to be determinative for the Al atoms per unit: It shifts to a lower wave number with increasing number of Al atoms in the framework tetrahedral sites. More specifically, clinoptilolite (6 atoms per formula unit) gives a band at 1059 cm-1 while heulandites (9 Al atoms per formula unit) gives a band at 1022 cm-1 [7].

Fig.4. FTIR spectrum of the Hesarbon zeolite.

The next strongest band, at 465.91 cm-1, is assigned to a T–O bending mode. The intensity is independent on thedegree of crystallinity. The vibrations in the region 1600–3700 cm-1 can be assigned to the presence of zeolite water. The isolated OH- stretching (at 3617.3 cm-1) is attributed to interaction between the water hydroxyl and the cations present. The other bands are attributed to the hydrogen bonding of the water molecule to surface oxygen (3441.12 cm-1) and to the bending mode of water (1635.42 cm-1).

References [1] K.D. Mondale, R.M. Carland, F.F. Aplan, 1995. The comparative ion exchange capacities of natural sedimentary and synthetic zeolites.Miner. Eng. 8 (4–5), 535–548. [2] R.W. Tschernich, 1992. Zeolites of the World. Geoscience Press, Phoenix. [3] L. B. McCusker, ChBaerlocher, Introduction to Zeolite Science and Practice - 3 rd Revised Edition, J. Cejka, H. van Bekkum, A. Corma and F. Schiith, Elsevier B.V.,2007 , 13-36. [4] I. Ivanova, A. Kuznetsov, V. Yuschenko, E. Knyazeva, Pure Appl. Chem. 76 (2004) 1647. [5] R. Munson, R. Sheppard, Miner. Sci. Eng. 6 (1974) 19. [6] D. Zhao, K. Cleare, C. Oliver, C. Ingram, D. Cook, R. Szostak, L. Kevan, Micropor. Mesopor.Mater.21 (1998) 371. [7] W. Mozgawa, M. Sitarz, M. Rokita, J. Mol. Struct. 512 (1999) 251.


Fabrication and comparison of NiO nanoparticles by acid and base and study of this

substance in the catalysis usage

Fatemeh Moosavia, A. Baharib,*, K.Taghavib, S. Asadolahzadehc a Department of Chemistry, Payam Noor University of Sari, Mazandaran, Iran

b Department of Physics, University of Mazandaran, Babolsar, Iran c Department of Physics, Islamic Azad University of Fars Research and Science, Iran

*[email protected] 1.Introduction Nanosized nickel oxid(NiO) has been under extensive investigations for decades as a kind of important inorganic material because a p-type semiconductor with band gap of 3.6 ev[1,2], is widely used in many field such as gas sensors, fuel cell, electrodes, magnetic material and catalysis, etc[3]. A large number of chemical methods that satisfy this requirement have been developed such as sol- gel, hydrothermal and emulsion method. Sol- gel process has been proven to be a useful technique for generating metal oxides with unusual properties. The sol- gel process always includes four steps: hydrolysis, polycondensation, drying and thermal decomposition[4,5]. The properties of the final products strongly depend on the precursors of the metal. In this work we were used of sol- gel method for prepared NiO with crystalline walls by the utilization of citric acid and KOH base. Citric acid is used as a ligand and the structure of the citric acid prevents the close contact of individual particles. The obtained NiO was characterized by X-ray diffraction (XRD) and Scanning electron microscope (SEM) techniques. 2.Experimental Synthesis 1: At first hexahydrated nickel nitrate (Ni(NO3)2.6H2O) was dissolved in dilute deionized water to form solution 0.7 M. Then 2 M KOH was added slowly drop wise, under stirring and room temperature into the solution until PH approached 9. The obtained green precipitate was filtered out and rinsed with dilute deionized water until PH was about 7. Then dried at 80 C for 24 h and calcining at 700 C. Synthesis 2: Primarily, 4.6 g (Ni (NO3)2.6H2O) and 4.2 g citric acid were dissolved in dilute deionized water separately. Then the nickel solution was added to other with previous condition by PH, 2.5 until PH approached 1. After a week stirring, the obtained a highly viscous residual was dried at 100 C and annealed at 300, 500 and 700 C. 3.Results and Discussion The structure and phase composition of the samples have determined by XRD diffraction measurements (figure 1). All of the five dominated peaks at high temperatures, labelled with miller indexes, indicate the NiO face- centered cubic phases. These peaks were appeared at 37.2 , 43.3 , 62.8 , 75.5 and 79.4 . The sample structure (see figure 1(right)) shows quite amorphous structure at room temperature, whilst it leads to crystallization structure at 300 C. This pattern relevant to samples annealed at 300˚ -700 C shows salient ˚growing of the peaks. These issues, however, indicate of the nanoparticles size increased which confirmed in X-powder measurement (based on Debye- Scherrer equation), and the measurement result, as an example is

coscKD

Debye-Scherre formula

20 30 40 50 60 70 800

10

20

30

40

50

60

70

80

90

100

110

120

130

140

250C

7000C

(222)(311)(220)

(200)(111)

Inte

nsity

(a.u

.)

2theta(degree)

20 30 40 50 60 70 800

50

100

150

200

250

300

350

400

450

500

7000C

5000C

3000C

1200C

(222)(311)

(220)

(200)

(111)

Inte

nsity

(a.u

.)

2theta(degree)

Where D is the crystallite size of nanoparticle, kα is a constant (0.94), λ is the wavelength of X-ray (Cukα = 1.5406 Å), β is the true half- peak width, and θ is the half diffraction angle of the centered of the peak in degree. Figure 3 shows SEM images of NiO obtained by KOH and citric acid. As it seen, the prepared NiO nanoparticles by KOH are spherical and bigger and more uniform than citric acid.

References [1] A. Bahari, P. Morgen, Z.S. Li, Surface Science, 600. (2006) 2966-2971. [2] A. Bahari, P. Morgen, Z.S. Li, Surface Science, 602. (2008) 2315-2324.

Fig.3. Scanning morphology of NiO prepared by (left) KOH and (right) citric acid.

Fig.1. XRD pattern of NiO prepared by (left) KOH and (right) citric acid.

Fig.2.The size of (left) 39 nm, (right) 15 nm determined with X-powder method.

[3] Y. Wu, Y. He, T. Wu, T. Chen, W. Weng, H. Wan, Materials Letters, 61. (2007) 3174–3178 [4] I. Hotovy, J. Huran, L. Spiess, Materials Science, 39. (2004) 2609 – 2612. [5] C. L. Shao, H. Y. Guan, S. B. Wen, B. C. Xing, H. Yang, J. Gong, Chinese Chemical Letters, 3.(2004) 365-367.


The effect of LSCO nanoparticles on nano electro mechanical systems

NedaGhorbanzadeha,A.Baharib,*, K.Taghavib,A. Jafarib, S.H.Moosavib

aDepartment of Physics, Islamic Azad University Research and Science of Fars, Iran bDepartment of Physics, University of Mazandaran, Babolsar, Iran

bDepartment of Physics, Islamic Azad University of Sari, Iran bDepartment of Physics, Islamic Azad University Research and Science of Hamedan, Iran

E.mail: [email protected] 1.Introduction

Some issues are threatening the use of ultra thin silicon dioxide as a suitable gate dielectric of current and next CMOS (Complementary Metal Semiconductor) transistors due to leakage and tunneling currents and boron diffusion through the ultra thin gate dielectric. Many researchers [1-4] have studied insulator materials to find a new and good gate dielectric to replace silicon dioxide in the CMOS devices. We have tried to synthesis LSCO dielectric materials with sol gel method to see if they (with the equivalent oxide thickness), can fill this gap. The results of recent research indicate that the introduction of LSCO nanoparticles in silicon matrix results in change of dielectric structure of a number of insulator materials. These systems can show different behaviors at different temperatures and the rate of precursors. Perovskite materials act as an obstacle towards soaring of leakage currents exponential function [4,5]. In the present work, the gate dielectric properties and structures have been studied by using XRD, SEM techniques and the size of nano LSCO crystallites is measure with X- powder method.

2.Experimental

To synthesis of LSCO materials, ( La0.5Sr0.5)CoO3 ,(La(No3)36H2O),(Co(No3)26H2O), (Sr(No3)2) have been used. These precursors were dissolved in distilled water at 90 0C with the La/Sr/Co ratio of 1/1/2, followed by the addition of 5 wt.% polyvinyl alcohol (PVA). The resulting solution (after 48 h stirring) was refluxed for 24 h at 110-120 0C. During reflux, the solution concentration was modified to be 0.5 M by distillation.Shortly after that, prepared colloidal solution was dried in 80 0C in oven over 3 days. The procedures have been repeated at 500,700, and 9000Ccalcinated temperatures.

3.Results and discussion

Figure 1(left) shows some sharp and broad peaks in XRD patterns, in which broad peak in figure 1(right) as an example of X- powder measurement shows a relatively amorphous structure and the other peaks are labeled to index miller are attributed to crystallite phases.


Fig.1. Left: XRD patterns of LSCO.Right:The size of 13nm determined with X-Powder method

Fig.2. Surface morphology of LSCO to a crystallization temperature (5000C)

Figure 2.show prepared material LSCO ( with different magnifications ) has amorphous structure which can reduce the leakage, tunneling current as well as some light atoms through the LSCO gate dielectric. The modification of Scherre estimation is also done in X- powder method as revealed in figure 1 (Right).

References

1. A.Bahari, P. Morgen and Z.Li, Surface Science,602, (2008),2315. 2. A.Bahari, Z.S. Li and P. Morgen, Surface Science, 600,(2006), 2996. 3. S.j.Yu and T.He, International Journal of Hydrogen Energy,36,(2011),6894. 4. Y.Liu, Journal of alloys compound ,77,(2009), 860. 5. H.P. Ding and X.J. Xue, Journal of alloys compound, 496, (2010), 683.


Production and scrutiny of mesoporousNiO particles by the bare sol- gel method

Khadijeh .Taghavia, A. Baharib,*, F. Moosavib, N. Ghorbanzadehb, N.Araghib

aDepartment of Physics, University of Mazandaran, Babolsar, Iran bDepartment of chemistry, Payam Noor University of Sari, Mazandaran, Iran

bDepartment of Physics, Islamic Azad University of Fars Research and Science, Iran bDepartment of Physics, Islamic Azad University of Hamedan Research and Science, Iran

*[email protected] 1.Introduction NanoscaleNiO has attracted tremendous interest, and various novel NiOnano structures were fabricated, e.g., nanoparticles, nanosheets, nanorods, nanowires, hollow spheres and porous solid[1,2]. Among all oxides, nickel oxide has been widely used in catalysis, battery cathodes, gas sensor, and magnetic materials[3,4]. The catalysis obtained by metal oxide with annealed hydroxides usually have low surface area because of precipitation of the tiny particles and demonstrate vain catalytic properties[3,4]. ThereforNiO with a comparatively large surface area and crystalline walls applicated in the catalytic field.Mesoporous metal oxides usually consist of amorphous walls and the crystallization by calcination results in the collapse of the mesoporous structure. It is proved that stearic acid (SA) has high strength disperse metal precursors due to its carboxylic acid group and long carbon chain. In this work was synthesized the mesoporousNiO via sol- gel process and was examined the structural properties of sample by X-ray diffraction (XRD) and scanning electron microscopy(SEM) technique. 2.Experimental At first 25g stearic acid was melted at 90 C ˚ in air. Then 10g hexahydrate nickel chloride (NiCl2.6H2O) was added into it and the obtained solution was heated at 150 C in oven. After ˚2h was generated a homogeneous and transparent sol.Then was cooled at room temperature to form gel. This gel was very hard and had two colours of turquoise and light green. Finally, the gel was annealed at 300 and 700 C. The obtained gray powder was mesoporousNiO.˚ 3.Result and Discussion Figure1. exhibits XRD patterns of the mesoporous samples. Difffraction peaks with correspond to (111), (200), (220), (311), (222) planes, at 37.2 , 43.2 , 62.8 , 75.4 and 79.4 . ˚ ˚ ˚ ˚ ˚This spectra show that sample was amorphous at 150 C and crystalline phase hasbeen happen ˚at 300 C. Growing of peak was indicated increase of nanoparticles size wh˚ ich approved by X-powder results in figure2.(Basedon Debye-Scherrerformula). By this method the nanocrystalline size was changedfrom 35nm to 39nm.

coscKD (Debye-Scherre formula)

Where D is the crystallite size of nanoparticle, kα is a constant (0.94), λ is the wavelength of X-ray (Cukα = 1.5406 Å), β is the true half- peak width, and θ is the half diffraction angle of the centered of the peak in degree.


20 30 40 50 60 70 80

0

50

100

150

200

250

300

350

400

(220)

(222)(311)

(200)

(111)

Inte

nsity

(a.u

.)

2theta(degree)

Fig.2.The size of (left) 35 nm, (right) 39 nm determined with X-powder method.

Figure3. shows SEM images of NiO morphologyat 700 C˚ . As it clearly seen, meso structure of NiO with crystallite walls was obtained by this process. This nanoparticles is almost spherical.

References [1] W.Xing, F. Li, Z. Yang, G.Q. Lu, Sources, 134.(2004)324-330. [2] T. Sre, S. Cha, S. Ngam, S. Yo,Colloids and Surfaces, 296.(2007)222-229. [3] A. Bahari, P. Morgen, Z.S. Li,Surface Science, 600. (2006)2966-2971. [4] A. Bahari, P. Morgen, Z.S. Li,Surface Science, 602. (2008) 2315-2324.

Fig.1. XRD patterns of samples at (up) 700°C, (middle) 300°Cand (down) 150 C.˚

Fig.3. Scanning morphology of NiOwithmagnification(left) 15 and (right) 30.


Growth and investigation of nanostructural properties of perovskitenano tubes

SalilehAsadollahzadeha,A.Baharib,*,A.Ghiasianb, aDepartment of Physics, Islamic Azad University Research and Science of Fars,Iran

bDepartment of Physics, University of Mazandaran, Babolsar, Iran bDepartment of Physics, Islamic Azad University Research and Science of Hamedan,

Iran E.mail: [email protected]

1.Introduction Perovskiteoxide exhibit a wide range of functional properties, such as ferroelectricity, piezoelectricity and non-linear dielectric behavior. This properties are indispensable for application in microelectronic devices. Recent advances in science and technology of perovskite oxide have resulted in the future size of microelectronic devices down-scaling into nanoscale dimension [1-3]. At thenanoscaleperovskite oxide display novel physical properties that are different from their bulk and film counterparts[3]. Recent utilizations of perovskite compound in conductor oxides and specially in ferroelectric devices caused these materials to be comforted on researcher’s notice[4-6]. In this study, the effects of LSCO ((La0.5Sr0.5)CoO3 ) have been synthesized by sol-gel method. We have performed structural properties and nanostructural traits of synthesizedperovskite and nanocrystalls size with XRD and SEM techniques. Consequences of this work can be used as a part of nano electro mechanical oxide’s electrodes that investigation of effect of nanoparticles LSCO on this compound is very important. 2.Experimental The following materials and reagents were used: lanthanum nitrate (La(NO3)3 6H2O), strontium nitrate (Sr(NO3)2), cobalt nitrate (Co(NO3)36H2O) and polyvinyl alcohol (PVA). . These precursors were dissolved in distilled water at 90 0C with the La/Sr/Co ratio of 1/2/1, followed by the addition of 4 wt.% polyvinyl alcohol (PVA). The resulting solution (after 72 h stirring) was refluxed for 24 h at 100-110 0C. During reflux, the solution concentration was modified to be 0.5 M by distillation. Shortly after that, prepared colloidal solution was dried in 820C in oven over 90 hours . The procedures have been repeated at 9000C calcinated temperatures. 3.Results and discussion We have considered nanostructural properties of perovskiteis obtained synthesis with X-rey diffraction and scanning electron microscope (SEM ). Outcomes of this study can be utilized in cases alike 3D memory devices, nano scale fluidity control systems and nano scale electro-producers.


Fig.1. Up. XRD patterns of LSCO. Down: The size of 73nm determined with X-powder method.

Figure 2.show prepared material LSCO ( with different magnifications ) has crystalline structure . The modification of Scherre estimation is also done in X- powder method as revealed in figure 1 (Right). References 1.C. Vijayakumar, H. Padma Kumar, S. Solomon, J.K. Thomas, P.R.S. Warriar and J. Koshy, Bull Material science,31,(2008),719-722. 2. Z. Xinhua, L. Zhiguo and M. Naiben, Journal of Materials Chemistry, 20,(2010) ,4015. 3. j. S. Yu and T. He, International Journal of Hydrogen Energy,36,( 2011), 6894. 4. H.P. Ding and X.J. Xue., Journal of alloys compound, 496, (2010),683. 5. A. Bahari, Z.S. Li and P.Morgen, Surface Science , 600,(2006) ,2996. 6. A. Bahari, P.Morgen and Z.Li,, Surface Science, 602,(2008),2315.

Fig.2. Surface morphology of LSCO 1/2/1 to a crystallization temperature 9000C


The removal of water hardness of steam boilers by poly Acrylamide-co-Acrylic acid/Clinoptiolitenano composite

M. NurmohammadBeigi,a,cH. Alikhanib, M.Zendehdelb,c,* aDepartment of Chemistry, Faculty of Science, Islamic AzadUniversity, Arak, Iran

bDepartment of Chemistry,Faculty of Science, Arak University, Arak, Iran cArak Science and Technology Park, Arak, Iran E-mail address:[email protected]

1.IntroductionDeposition is amajor problem in the operation of steam generating equipment.

Deposition is the accumulation of material on boiler surfaces that can cause over heating and loss of

efficiency due to lost heat transfer, as well as circulation restrictions. Calcium and Magnesium cations

are caused total hardness and formed deposits. Deposits usually fall into one of two types: Scale that

is crystallized directly on tube surface and sludge deposits consisting of various salts that have

precipitated elsewhere which consist of discrete and usually non-uniform particles [1]. Ion exchange

resins are insoluble substances containing loosely held ions which are able to exchangewith other ions

in solutions which come in contact with them. The synthetic resins are used primarily for purifying

water, but also for various other applications including separating out some elements. Synthetic ion

exchange materials based on coal and phenolic resins were first introduced for industrial use during

the 1930. In the last decade, resins consisting of polystyrene with sulphonate groups to form cation

exchangers or amine groups to form anion exchangers were developed. These two kinds of resin are

still the most commonly used resins today. In water softening acationic resin in the sodium form is

used to remove hard metal ions such as Calcium and Magnesium from the water. This ions are

replaced by an equivalent quantity of sodium, so that the total dissolved solids content of the water

remains unchanged as does the PH and anionic content [2].Although ,this material have many

advantage but absorption capacity and thermal stability of it is very low. Recently, the adsorption

process with strong affinity and high loading capacity for targeted metal ions has developed much

attention which has paid to modification of superabsorbent.Although much preparation have focused

on the improvement of the swelling ability, gel strength, mechanical and thermal stability of

superabsorbent, but adsorption of hard metals by these composites is very important for selection of

suitable adsorbent to metals removal from aqueous solutions.

2.Experimental


In this study, poly acrylamide-co-acrylic acid/clinoptilolitenanocomposite was synthesized. These

materials were characterized by using FT-IR spectroscopy, XRD, TGAandSEM.Also, adsorption

experiments were evaluated in batch equilibrium mode. All experiments were done by mixing 25 mL

of boiler water withdifferent quantities of poly acrylamide-co-acrylic acid/clinoptilolite (table

1).3.Result and discussion

Result show that all ions trapped on the nanocomposite.

References [1] A. Banweg, Shreir's Corrosion, 4(2010)2971-2989.[2]E. Korngold, S. Belfer, C. Urtizberea,Desalination, 104 (1996) 197-201.[3] M. Zendehdel, A. Barati, H. Alikhani,Polym. Bull,67 (2011) 343–360.

before after

Total Hardness 408 0

Calcium Hardness 142 0

Magnesium Hardness 23 0

PH 7.8 8

TDS 343.04 362.24

EC 536 546

′ P ′ - Alkalinity 0 0

′ M ′ - Alkalinity 285.48 270.84

NO3 3 3

SO3 0 0

SiO2 0.3 0.3

PO4 2 2

NH3 0.1 0.1

N2H4 0.1 0.1

Fe 0 0


Microwave assisted synthesis of cobalt aluminate pigment from Co(II)-exchanged zeolite A

SoheilSaffarya, AlirezaMirhabibia,*, HosseinEsfandiara, ToorajEbadzadehb

aSchool of Metallurgy & Material Science, Iran University of Science & Technology, P.O. Box: 16845-161,

Tehran, Iran bCeramic Division, Materials & Energy Research Center, P.O. Box 14155-4777, Tehran, Iran

*Corresponding author. Tel:+98 21 77240540, E-mail address: [email protected]

1. Introduction

Cobalt aluminate spinel, CoAl O , which gains its royal blue colour from tetrahedral coordinated Co(II) ions, has been used extensively as an inorganic pigment (1). There are some reports about synthesis of this pigment from Co(II)-exchanged zeolites (1, 2). Extraordinary ion-exchange ability of zeolites enable us entering cobalt ion into zeolite structure uniformly. This elemental distribution of cobalt beside aluminum of the framework leads to a uniform nucleation of CoAl O after heating.

2.Experimental

Cobalt-exchanged zeolite A was prepared by ion-exchange treatmentof synthesized zeolite A in an aqueous solution of cobalt chloride at 85 °C. The Co(II)-exchanged zeolite A calcined with microwave irradiation for 15 minutes. This calcination time is much less than what are reported in the previous works which conventional heating have been used in all of them with 10 to 14 hours needed for completing the reaction.The prepared sample was grinded and characterized by X-ray diffraction(XRD), Scanning Electron Microscope (SEM), CIE-Lab color measurement and Fourier transformation infrared (FTIR).

3. Result and discussion Figures 1 and 2 show thesample color and SEM of it, respectively. The cubes of cobalt aluminates spinel structure can be seen in SEM image.

Figure. 1. Sample heated at 1200 °C.


Figure.2. SEM image (secondary electron analysis) of sample heated at 1200 °C.

Co-exchanged zeolite A which has an elemental distribution of cobalt beside aluminum is an appropriate sourcefor uniform nucleation of CoAl O . Moreover, using microwave as a heating source considerablydecreasesthe synthesis time compared with the time needed inconventional heating.

1- Lodge. M.T.J., Edwards. P. P., Anderson. P. A., Jones. M.O., Gameso. I., Synthesis of micro-crystals of transparent cobalt aluminate, shrouded in siliceous material, from Co(II)-exchanged zeolite X. Polyhedron, 25.(2006) 568–574.

2- Weidenthaler, C., Mao, Y., Schmidt, W., Mixed CoNiAlSpinels Synthesized from Ion- Exchanged Zeolite A and X. Studies in Surface Science and Catalysis, 158. (2005) 415-422.


Kinetic study of phenol oxidation reaction with H2O2 and by using of transition metal Schiff

base complexes encapsulated intra zeolite-Y

. Mobinikhaledikbar, A*Mojgan ZendehdelZohreh Mortezaei,

Chemistry Department, Arak University,Arak,38156-88138,Iran

E-mail: [email protected])(*phone number: 09183644690,

Abstract

Heterogenization of homogeneous catalysts enhances their activity, selectivity, thermal stability and

reusability. Further, the heterogenization has advantages over their soluble counter parts of easy

separation from the reaction mixture,leading to operational flexibility and their facile regenarability.

Immobilisation of homogeneous catalysts on insoluble polymer support, or their encapsulation in

nanopores materials like zeolites and mesoporous materials like MCM-41 are some common methods

to produce heterogeneous catalysts [1].

In this work new nanocomposites by using of encapsulated transition metal Schiff base complexes

intra zeolite-Y was prepared. The first time we added transition metal (M=Cu(II),Mn(II),Co(II),Ni(II))

to nanocavity of zeolite-Y that formed M(II)-NaY. After tetradentate Schiff base ligands such as H2L1:

(C22H20N2O2) and H2L2 (C24H18N2O2) have been introduced to nanopourse M(II)/ Y zeolite with flexible

ligand method.

The new Host-Guest Nanocomposite Materials (HGNM) were characterized by several techniques:

chemical analysis, spectroscopic methods (DRS, FTIR, XRD, TGA and BET). Results show that these

complexes encapsulated onto zeolite and was used for oxidation of phenol to catechol and

hydroquinone with H2O2 as oxidant in CH3CN as solvent. Considration of yield show that following

order for the H2L1 ligand: [Cu(L1)]/NaY > [Mn(L1)]/NaY > [Co(L1)]/NaY > [Ni(L1)]/NaY

And the following order for the H2L2 ligand:

[Ni(L2)2]/NaY > [Co(L2)2]/NaY > [Cu(L2)2]/NaY > [Mn(L2)2]/NaY Also we considered the effect of different factors on percent of products in oxidation of phenol such as:

type of oxidant and solvent, amount of catalyst, temperature. Results show that the catalytic activity of

encapsulated complexes in oxidation phenol have been increased than the neat complexes and the

catalytic reaction occurred via a radical mechanism.

The objectives of our kinetics analysis were to determine the reaction rate constant (k), its associated

Arrhenius parameters ,and the reaction orders for phenol (α), H2O2 (β) for the power-law rate

expression in Eq. 1: Rate = k[Phenol]α[H2O2]β

If we consider concentration H2O2 much more than estokiometri ratio, therefore: [H2O2]β= constant ,

and J= -d[Phenol]/dt → -d[Phenol]/dt= K[phenol]α

-Ln(1-X) = Kt


that X was the phenol conversion to products that obtained after specific time (t).

LnK= -Ea /RT + LnA :(Arrhenius) Eq.2 To determine the reaction order with respect to phenol, we measured the phenol conversions obtained

at different temperature [2,4]. Then we carried out the integration indicated in Eq. 2 for different

integer and half-integer values for the phenol reaction order [3] and plotted the data as -Ln(1-X) vs. t.

The value of α that resulted in a linear plot was selected as the phenol reaction order. Figures 1 and 2

displays this integral method plot for a rate law (at 80 °C) that is first order in phenol (α= 1).

0

0.2

0.4

0.6

0.8

1

0 0.5 1 1.5

-Ln(

1-X

)

Time (h)

Figure 1. Plot -Ln(l-X) vs.t for Figure 2. Plot -Ln(l-X) vs. t for [Cu(L1)]/NaY (80 °C) [Ni(L2)2]/NaY (80 °C)

The Kinetic of phenol oxidation with excess H2O2 over [M(Ln)m]/NaY catalysts at several temperatures of 40 ،60 and 80°C was investigated. Results show that a pseudo-first order with respect to phenol.

References

[1] M. Salavati-Niasari, M. R. Ganjali, P. Norouzi, J.Porous.Mater, Springer (2006).

[2] S. Gopalan and P. E. Savage ,AIChE Journal, 41. (1995) 1864-1873.

[3] T. D. Thornton and P. E. Savag ,AIChE Journal, 38. (1992) 321-327.

[4] A. Fortuny, C. Ferrer, C. Benoa, J. Fon, A. Fabregat ,Catalysis today, 24. (1995) 79-83.


Investigation of ultrasonic and microwave-assisted aging effects on the static

hydrothermal synthesis of sodalite zeolites prepared from perlite using Box-Behnken

experimental design

Neda Asemi, a Seyed Naser Azizib* and Mohamad Hossein Fatemic a,b,cAnalytical division, Faculty of Chemistry, University of Mazandaran, Babolsar, Po Box: 47

416–95447, Iran * Phone:01125342393, Fax:01125342350, E-mail:[email protected]

1.Introduction Perlite or pearl stone is a natural glass generally of equivalent composition to granite, which has formed by rapid cooling of viscous lava or magma. Perlite is mainly composed of silica, aluminum, potassium and sodium [1].The synthesis of zeolites from low-cost silica and alumina sources has been the aim of many experiments [2]. In this experiment, perlite was used as a low-cost source of Si and Al to synthesis of sodalite zeolite. The synthesis of sodalite zeolite from perlite by using the alkaline hydrothermal treatment under saturated steam pressure was investigated. A statistical Box-Behnken Design (BBD) of experiments was employed to evaluate the effects and interactions of the process variables such as type of aging, aging time and hydrothermal crystallization time on the crystallnity of synthesized sodalite zeolite. The optimum conditions for maximum crystallinity of sodalite zeolite were obtained as microwave-assisted aging, 1h min aging time and 8 h hydrothermal crystallization time from statistical analysis of the experimental results using BBD .The synthetic samples were characterization by XRD, FT-IR and SEM techniques. The results showed that the microwave-assisted aging can shorten the crystallization time and reduced the crystal size to form sodalite zeolite. 2.Experimental

The starting material used was raw perlite with a grain size of 40 µm (79.79 wt.% SiO2; 10.66 wt.% Al2O3). The starting material (perlite) reacted with NaOH 5 M and with the ratio (w/v) of solid to liquid 1:40 and the temperature was used at 100 oC at various times [4], in a 80 ml stainless steel reactor. The chosen effective factor for BBD analysis was as Type of aging techniques (microwave, ultrasonic assisted and without aging), aging time (20, 40 and 60 min) and hydrothermal crystallization time (24, 15 and 8 h) while hydrothermal crystallization tempertature of 100 ºC and the ratio of perlite to NaOH (5 M) solution 1:40 w/v were kept as constant input parameters. The solid products were characterized by XRD, FT-IR and FE-SEM.


In the synthesis experiments with NaOH solutions sodalite zeolite were synthesized. The XRD patterns of synthesized zeolite which were proposed using BBD (by statgraphics software) is shown in Fig. 1. From the obtained results, it can be concluded that the aging step plays an important role in shortening the crystallization time in synthesizing sodalite zeolite. If no aging of the solution in the synthetic process was performed, crystallization time 24 h would be required to obtain highly crystalline zeolite Figure 1a. In the cases of ultrasound-assisted aging for 1 h and microwave-assisted aging for 1 h prior to heat treatment, the crystallization time could be efficiently shortened and reduced to 15 h and 8 h (Fig 1b and 1c) and the study of FE-SEM images of synthesized zeolite indicates (was not shown) that the crystal size of synthesized zeolite become larger by 1 h ultrasonic, while


microwave assisted aging led to the aggregation of smaller crystal size, probably due to the creation of more nuclei by this aging techniques (Figure 2). By Box-Behnken design of experiments we have been able to experimentally improve the crystallinity of sodalite zeolite, which requires a long crystallization period under the conventional method without any pretreatment. Microwave aging technique enhances the rate of nucleation and increase the nucleation rate during the crystallization process. The optimum conditions for maximum crystallinity of sodalite zeolite were obtained as microwave-assisted aging, 1h min aging time and 8 h hydrothermal crystallization time from statistical analysis of the experimental results using BBD .

Figure 1. X-ray diffraction of synthesized soldalite zeolite using 24 h crystallization time without any aging (a), 15 h crystallization time with ultrasonic assisted (b) and 8 h crystallization time with microwave assisted aging techniques

References 1. Z. Talip, M. Eral and Ü. Hiçsönmez, Journal of Environmental Radioactivity, 100. (2009) 139-143. 2. P. Kongkachuichay and P. Lohsoontorn, ScienceAsia, 32. (2006) 13-16. 3. G. Vijayakumar, M. Dharmendirakumar, S. Renganathan, S. Sivanesan, G. Baskar, K. P. Elango, Clean, 37. (2009) 355 – 364. 4. P. Wang, B. Shen, J. Gao, Catalysis Today, 125. (2007) 155–162.


Enhancing the adsorption of Ni (II) by methionine templated analcime

Salma Ehsani Tilami,a Seyed Naser Azizia,*

a University of Mazandaran, Babolsar,47416-95447, Iran * Seyed Naser Azizi,+98 1125342350, +981125342350, E-mail: [email protected]

1.Introduction Heavy metals are the most important pollutants in the environment and widely found in surface waters, which come from natural sources and industrial [1]. Among metals, Ni is a commonly toxic metal in natural ecosystems. The most common adverse health effect of nickel in humans is an allergic reaction in direct contact with the skin caused by jewelry or other items containing nickel [2]. Nowadays, a number of low cost adsorbent materials such as zeolites are available to remove metal ions [3-5]. Several investigations have been conducted to obtain adsorption capacity of heavy metals on zeolite [6]. For this propose in this study, the effect of methionine amino acid as a template for analcime zeolite has been studied and difference on Ni (II) adsorption ability of two type analcime zeolite (with and without methionine) have been investigated.

2.Experimental

Methionine templated analcime and free templated analcime were provided according to the reported procedure [7]. The adsorption tests were performed by batch technique at 30 C for optimizing the pH and Time intervals. For Langmuir and Freundlich isotherms studies different initial concentrations of Ni (II) were prepared. The solutions pH was adjusted by HCl and NaOH solution.


The experimental equilibrium data for Ni (II) adsorption on methionine templated analcime and free templated analcime were fitted by the Langmuir and Freundlich isotherms and illustrated in figure 1. Regression coefficients obtained from the Freundlich isotherm were higher than Langmuir isotherm, which suggested the heterogeneous adsorption of Ni (II) on methionine templated analcime and free templated analcime zeolite. From the Langmuir model, the calculated parameters at the maximum uptake of Ni (II) for methionine template analcime was 40 (mg/g) and for free template analcime was 32.2(mg/g). Based on the Freundlich isotherm, the maximum adsorption capacity of Ni (II) was 1.42 (mg/g) for methionine template analcime while it was 1.38 (mg/g) for the free templated analcime. The isotherms indicated that zeolite containing methionine has a better ability for adsorption Ni (II). Formation of Ni-s bonding causes to increase adsorption of Ni (II). So applying the methionine not only as a

template but also as a modifier to enhancing the adsorption ability of zeolites has been proved.


Figure 1. (a) Freundlich and (b) Langmuir of Ni (II) adsorption on methionine templated analcime and free templated analcime

References

[1] S. Wang, H. Wu, J. Hazard. Mater136. (2006) 482-501. [2] F. William, J. Sunderman, Preventive Medicine 5. (1976)279-294. [3] G. Crini, Biores. Techn 97.(2006)1061-1085. [4] E. L. Cochrane, S. Lu, S. W. Gibb, I. Villaescusa, J. Haz. Mat137. (2006) 198-206. [5] X. G. Li, F. Hao, M. R. Huang, Prog. Chem20. (2008) 233-238. [6] A.E. Turkman, S. Aslan, I. Ege, Fresenius Environ. Bull13. (2004)574-580. [7] S. N. Azizi, S. Ehsani Tilami, Anorg. Allg. Chem 635.(2009) 2660-2664.


Synthesis of nanostructure SBA-15 using Stems of Sorghum Ash as silica source and its

application for electrocatalytic oxidation of methanol Elham Chiani,a S.N. Azizi a,*

a elham chiani, Babolsar, P.O.Box: 47416-95447, Iran * Seyed Naser Azizi . +981125342350, +981125342393, [email protected]

1.Introduction

high percentage of amorphous SiO2 is produced of Stems of Sorghum Ash (SSA) obtained from open field burning at below 700C. SSA can be considered as a new economically viable raw material to produce silica or to be used as silica resource. The synthesized zeolite was characterized using scanning electronic microscopy, X-ray diffraction, FT-IR techniques, thermal analysis and superficial area by N2 adsorption method and Transmission electron microscopy. In direct methanol fuel cells (DMFCs), methanol is used as a fuel and a great deal of interest exists in the development of materials with capability for the electrocatalytic oxidation of methanol [1]. The use of zeolites as supported electrodes represents minimizing overvoltage effects for catalytic oxidation of methanol [2, 3].

2.Experimental

The modified carbon paste electrode was prepared by incorporation of Ni (II) zeolite in the carbon paste matrix. The electrochemical oxidation of methanol was investigated at the surface of this modified electrode in alkaline solution using cyclic voltammetry and chronoamperometry methods. The effect of some parameters such as scan rate of potential, concentration of methanol, amount of Ni (II) zeolite was investigated on the oxidation of methanol at this electrode.


the effect of methanol concentrations on the cyclic voltammetric shown, in low concentration of methanol, there are two anodic peaks; P1 (assigned to the couple α-Ni(OH)2/NiOOH) and P2 (assigned to the couple β-Ni(OH)2/NiOOH) [4,5]. When methanol concentration increases, the current density of the peak P2 increases significantly, while the peak P1 decreases and even disappears. Increasing concentration of methanol makes more NiOOH to be consumed. Cyclic voltammograms of Ni/SBA-15CPE at the various scan rates exhibits the strong dependence of the peak P2 on the potential scan rate. The peak P2 only arises at very low scan rates and it disappears at higher scan rates. The forward and backward potential step chronoamperometry of the modified electrode in the blank solution that showed an almost symmetrical chronoamperogram with almost equal charges consumed for the oxidation and reduction of the surface confined Ni (II)/Ni(III) sites.


-1000

-500

0

500

1000

1500

2000

0 0.2 0.4 0.6 0.8 1 1.2

I(µA

)

E(V)-5 0 0

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

2 5 0 0

0 0 .5 1 1 .5

I(µ A )

E (V )

p 1

p 2

Fig. 8: (A) Cyclic voltammograms of the Ni/SBACPE in the presence of 0.03 M Methanol at different scan

rates: (a) 20 (b) 50 (c) 100 (d) 200 (e) 400 (f) 600 (g) 800 mV s-1. (B) Zoomed cyclic voltammograms of

(a), (b), and (d) from main panel of (A).

References

[1] Ojani R, Raoof JB, Hosseini SR. Electrocatalytic oxidation of methanol on carbon paste electrode modified by nickel ions dispersed into poly (1,5-diaminoaphthalene) film.lectrochimca Acta 53.(2008) 2402. [2] Abdel Hamed RM, EI-Khatib KM. NieP and NieCueP modified carbon catalysts for methanol electrooxidation in KOH solution. Int J Hydrogen Energy35.(2010) 2517. [3] Golabi SM, Nozad A. Electrocatalytic oxidation ofmethanol on a nickeleporphyrin IX complex modified glassy carbon electrode inalkalinemedium.Electroanalysis 16.(2004) 199. [4] Subbaiah T, Mallick SC, Mishra KG, Sanjay K, Das RP.Electrochemical precipitation of nickel hydroxide. J Power Sources 112.(2002) 562. [5] Yi Q, Zhang J, Huang W, Liu X. Electrocatalytic oxidation ofcyclohexanol on a nickel oxyhydroxide modified nickelelectrode in alkaline solutions. Catal Commun 8.(2007) 1017.


Penological stage, plant height and grain yield of maize affected using clinoptilolite zeolite natural.

Ali Mahrokh*1 and Mojgan Zendehdel2

Maize and Forage plant Department, Seed and Plant Improvement Institute, Karaj, Iran E-mail: [email protected]

2 Department of Chemistry, College of Science, Arak University, Arak; Iran

1. Introduction

Zeolites are crystalline, hydrated aluminosilicate of alkali and alkaline earth cations possessing an infinite, open three-dimensional structure. Several studies indicated that NZ showed positive effects on plant growth. This study was considered the effect of natural Zeolite (Clinoptilolite) on phenological stage and grain yield of four maize cultivars. 2. Experimental The experiment was laid out as a split plot design based on randomized complete block with three replications in 2010 and 2011 at research field in Seed and Plant Improvement Institute, Karaj. Zeolite was used in four levels including 0, 5, 10 and 15 ton per hectare as main plots and four maize cultivars including KSC704, KSC700, KSC647 and KSC604 as sub plots. 3. Results and discussion The effect of using zeolite was significant (p≥ 0.01) for days to tussling, plant height and grain yield and it was also significant (p≥ 0.05) for anthesis – silking interval and it wasn’t significant for days to anthesis and silking. The different among cultivars was significant (p≥ 0.01) for days to tussling, anthesis and silking and it was significant (p≥ 0.05) for anthesis – silking interval and plant height and it wasn’t significant for grain yield. Using 5 ton per hectare zeolite increased grain yield significantly (24.25% more than control) and grain yield increased from 7770.9 to 9654.8 kg per hectare. The using more than 5 ton per hectare zeolite decreased grain yield. From the result of this experiment using 5 ton per hectare cliniptilolite natural zeolite and also cultivating KSC704 cultivar can be recommended for similar Karaj climate. Result of this experiment using 5 ton per hectare increased grain yield but using more zeolite (10 and 15 t/ha) decreased grain yield to control treatment. Probably, using more zeolite has increased soil moisture and less development of the root, increased root lodging and subsequently, decreased grain yield. Finally, it seems zeolite can be affect on anthesis-silking interval, plant height (table 2) and probably increase fertilizing system, photosynthesis assimilate and its can be useful for remobilization in filling grain stage.

Table 1- analysis of variance for phenological stage, plant height and grain yield.

Mean of squares Grain yield Plant height Anthesis-

silking interval

Days to silking

Days to anthesis

Days to tussling

df S.O.V

660318805.3** 83826.25** 384.00** 672.04** 40.04** 44.01** 1 year 10060515.8 250.43 3.68 3.17 2.58 2.82 4 Block(year)

19748496.9** 394.84** 5.59* 2.47 ns 5.01 ns 13.51** 3 zeolite 7697725.2 ns 472.66** 5.33 ns 1.40 ns 2.06 ns 0.59 ns 3 zeolite×year

842872.0 335.56 1.54 3.80 2.66 4.69 12 Error a 5142317.7 ns 260.74* 5.56* 147.38** 192.18** 255.78** 3 cultivar 11267567.4* 179.55 6.86* 4.15 ns 2.01 ns 5.03 ns 3 Cultivar ×year 5294919.8 ns 97.18 ns 1.75 ns 2.45 ns 0.89 ns 1.09 ns 9 cultivar×zeolite 1896765.6 ns 75.77 ns 2.19 ns 2.25 ns 1.11 ns 1.36 ns 9 cultivar×zeolite×year 2956893.0 75.97 2.34 3.02 0.96 1.95 48 Error b


Significant at the 5% and 1% levels respectively and ns: no significant. ** , *

Table2. Comparison of means of phenological stage (days), plant height (cm) and grain yield (kg /ha) affected using of clinoptilolite natural zeolite.

Grain yield (kg/ha)

Plant height (cm)

Anthesis-silking interval

Days to silking

Days to anthesis Days to tussling Experimental factors

Zeolite (t/ha) 7770.9b 186.26ab 6.08a 72.54a 66.45a 64.08b control 9654.8a 192.90a 5.33ab 71.79a 66.45a 63.95b 5 7724.2b 183.12b 5.41ab 72.33a 66.91a 64.95ab 10 8145.3b 187.57ab 4.91b 72.33a 67.41a 65.54a 15

cultivar 8912.1a 190.98a 4.79ab 73.95a 69.16a 67.16a Ksc704 8466.1a 186.74ab 5.50ab 74.70a 69.20a 67.62a Ksc700 8027.9a 184.26b 5.95a 69.54c 63.58c 61.04c Ksc647 7889.2a 190.88a 5.50ab 70.79b 65.29b 62.70b Ksc600

year 10946.5a 217.76a 3.43b 69.60b 66.16b 63.95b 2010 5701.2b 158.66b 7.43a 74.89a 67.45a 65.31a 2011

Means followed by similar letters in each column of each treatment are not significantly different whit Duncan test at 5% level of probability.

Reference Armandpisheh, O., H. Irannejad, I. Allahdadi, R. Amiri, A.GH. Ebadi and A. Koliaei. Application of Zeolite in Drought Stress on Vigority of canola seed (Zarfam cultivar).J. Agric. Envir. Sci. 5(6): 832-837(2009). Mompton, F. Laroca magica: Use of natural zeolites in agriculture and industry. Proc. Natl. Acad. Sci. USA., vol. 96, pp.3463-3470(1999). Turan, Z. M. Effect of natural zeolite on growth and yield of medicago Sativa L. Jornal of Agronomy. 5: 118-121 (2006).


Catalytic performance of iron-based catalysts supported on ZSM-5 Zeolite for CO hydrogenation

MostafaFeyzi*, JahangirShahmoradi, Mohammad Mehdi Khodaei

Kermanshah, P. O. Box +98-67149, Faculty of Chemistry, Razi University, Iran *Corresponding author. Tel./fax: +98 831 4274559, E-mail address: [email protected]

1.Introduction

Fischer-Tropsch synthesis (FTS) entails the conversion of CO and H2 to a spectrum of products mainly comprising alkenes and alkenes [1]. The development of highly active supported Fe catalysts, however, would be useful since it could reduce catalyst density and encourage catalyst application in fluidized or slurry reactor. Zeolites are interesting supports for this purpose. Additionally, most of the studies reported have been attempted to improve catalyst performance by promoting with additives such as K, Mn, Cr, Ru and Pd [2,3].

2. Experimental

All of iron based catalysts supported on ZSM-5 were prepared through using the following incipient wetness method. In order to prepare the Fe/ZSM-5 catalyst, ZSM-5 was impregnated with loading of x wt.%Fe (x = 2, 4, 6, 8, 10, 12, 14 and 15 wt.% based on the support weight), the catalysts test shows that 8 wt.% of Fe is the optimal amount for light olefins production. Then, 8wt.%Fe/ZSM-5 catalyst was impregnated with different wt.% of Mn. The impregnated was dried in an oven (120 ºC, 12 h) to give a material denoted as the catalyst precursor, subsequently calcined in a furnace to achieve the final catalyst.


The x Fe/ZSM-5 catalysts were prepared with differentloading iron were tested for the CO hydrogenation under reaction conditions (H2/CO=2/1, GHSV=2200 h−1, P=1 bar and T=250 C). According to the obtained results, the ˚catalyst containing 8wt %Fe presented the best catalytic performance compared to the other tested catalysts. X-ray diffraction for 8wt%Fe/ZSM-5 showed the tetragonal phase and demonstrated in Figure 1.The catalyst containing 8wt.% Fe was characterized with TEM (Figure. 2). It is obvious in this Figure that the crystal sizes were from 35–50 nm. This result confirmed the obtained results studied by using the Scherrer equation from XRD pattern;the 8wt%Fe/ZSM-5 catalyst precursor was characterized to measure the amount of weight losses as the temperature of the sample was increased. The TGA/DSC curves for this catalyst precursor were displayed in Figure. 3. The weight losses obtainedfrom TGA measurement were realized to agree fairly well with those expected for thedecomposition of nitrate compounds to oxides. For this catalyst precursor, the thermogravimetric curve seems to indicate two–stage decomposition. The first stage (20-125 C) is considered to˚ be the one caused by the physically removal of adsorbed species and dehydration. The second stage (180-580 C) is due to the decomposition of crystalline water and hydroxyl phases in precursor. Thermo gravimetric ˚curve revealed formation of stable oxides form of iron more than 580°C. In 580 C the sample loosed 13.5% of ˚its weight and this temperature was chosen for calcinations of catalyst. DSC measurement was performed in order to provide further evidence for the presence of the various species and evaluates their thermal behavior. By using of physical N2-adsorption-desorption, the specific surface area and pore volume of precursor were measured and demonstrated in Figure 4. In an effort to the influence of wt. %Mn on catalytic performance of 8% Fe nano-catalyst, the different weight’s percentages of Mn (based on the Fe weight), according to Table 1 were testedunder the same reaction conditions. Results proved that the catalyst with 30 wt.%Mn had the highest


0

100

200

300

123456789

wt.%Fe

(m2g-1)specific surface area

selectivity and the best catalytic performance to CO hydrogenation so it was chosen as optimal catalyst (8% Fe/2.4%Mn/ ZSM-5).

3. Conclusion

According to obtained results by usingZSM-5 zeolite as a support for Fe-Mncatalyst the catalytic performance of iron-manganese was increased.

Table 1

Reference:

[1] S.L. Gonz´alez-Cort´es, S.M.A. Rodulfo-Baecher, A. Oliveros, J. Orozco, B. Fontal, A.J. Mora, G. Delgado, J. React. Kinet.Catal.Lett, 75. (2002)3. [2] N. Lohitharn, Jr.J.G. Goodwin, E. Lotero, J. Catal, 255. (2008) 104. [3] M. Feyzi, M. Irandoust, A. A. Mirzaei, Fuel .Proces.Tech, 92.(2011) 1136.

0

50

100

1416

crystal size (nm)

wt% Fe

2 = 36

80 70 60 50 40 30 20 wt.%Mn43.1 46.6 50.2 53.9 62.4 70.5 69.8 CO conversion (%) 15.4 14.5 12.3 11.7 10.6 9.4 10.6 CH4

Prod

uct

sele

ctiv

ity

(%)

20.5 23.5 27.4 32.2 34.5 37.9 34.6 C2-C4 olefin 13.6 11.2 11.6 13.6 13.8 13.4 14.9 C2-C4 alkane 30.1 31.2 30.4 26.2 23.7 20.9 21.2 C5-C12 6.1 7.9 8.6 7.4 8.4 9.8 8.5 C13+14.3 11.7 9.7 8.9 9.0 8.6 10.2 CO2

Figure 4 Figure 5


Preparation of PEG-Zeolite nanocomposite and its application for controlled release of metronidazole drug

ForoozanSahrakar, M.Zendehdel

Address : Chemistry Department, Arak University, P.O. Box 38156-879, Arak, Iran E-mail address: [email protected]

1.Introduction During the past three decades, drug release technology has been developed rapidly and became one of the

most important fields in modern medication. Compared with conventional dosage forms, controllable

release system offers numerous advantages. Incorporation of the drug into a particulate carrier can protect

the active substance from degradation in vivo and in vitro. It also offers possibilities of targeting,

improves therapeutic effect, prolongs biological activity, controls drug release rate and decreases the

frequency of administration [1].In general biocompatible polymers are employed as carriers in controlled

drug release. Polymeric prodrug, as a conjugation of a drug with a polymer, has many advantages such as

increased drug solubility, prolonged drug release, increased stability and decreased toxicity. However, in

the controlled drug release systems based on polymers, model drugs are included into polymer matrix by

means of direct compression, wet granulation, or mechanical mixture. It is a problem for the drug to be

distributed homogeneously into polymer, which can affect drug release rates for different samples [2].

These problems can be solved by the preparation of polymer-porous material hybrids. The use of

nonporous materials as effective materials for a drug delivery system has received much attention in view

of their structural availability, inclusion capacity, and spontaneous dispersion in aqueous solutions [3].

Zeolites have a well-defined nanopore structure with a crystalline framework consisting of SiO4 and AlO4

tetrahedra. This framework contains open cavities in the form of channels and cages.One of the many

exciting potential pharmacological applications of zeolites is the possible encapsulation and or adsorption

of ions and molecules in their open framework, and then delayed release [4]. Metronidazole(MTZ), 2-

methyl-5-nitroimidazole-1-ethanol, is a nitroimidazole derivative with activity against anaerobic

protozoa, aerobic and microaerophilic bacteria. Common adverse effects of metronidazole involve the

gastrointestinal tract and the neurological system with high doses. Therefore, reduction of side effects of

metronidazole (plasma peak levels) while prolonging its action by using controlled oral dosage forms is

highly desirable.Metronidazole is slightly soluble in water and the MTZ- PEG conjugates present

increased solubility in water [5].Based on these general properties, In this work, we prepared PEG-

NaYnanocomposite using poly(ethylene glycol) of 600 withsodium zeolite Y, as drug charier.


2.Experimental

The prepared nanocomposites were identified using infrared spectroscopy. The results showed that drug

successfully linked with zeolite and no changes were happened in the metronidazole molecular structure.

The physical state of drug in the composite material was analyzed by Thermo gravimetric analyses (TGA)

and Differential scanning calorimetric (DSC). Also, we could obtain the percent of drug-loaded into PEG-

NaYnanocomposite by TGA diagram. The particle morphology was examined by scanning electron

microscopy (SEM) that exhibited the particles are in the nano size and same size. The powder X-ray

diffraction of the PEG-NaYnanocomposite before and after drug-loaded yield a typical pattern of

crystalline substances. This was agreement with other results. Then, the metronidazole release behavior

evaluated for the drug-loaded nanocomposite sample. we studied pH and temperature effects of

metronidazole release in the drug-loaded nanocomposite sample.

3.Results and discussion

The release fluids with different PH were prepared to investigate MTZ release process in body

temperature. Then, we investigated release behavior of drug-loaded nanocomposite sample in different

temperatures into solutions, including simulated intestinal fluid (SIF, phosphate buffer solution, pH=7.4),

simulated body fluid (SBF, pH=7.4),and simulated gastric fluid (SGF, HCl aqueous solution, pH=2).They

exhibited a similar delivery relationship. First, a fast release and then a slower release were observed.

Some MTZ molecules might be physically adsorbed on the outer surface on nanocomposite and other

MTZ were filled in the pore channels. We deduced that the molecules on the outer surface, were rapidly

release, while those molecules inside the pore channels were slowly released at simulated body fluid. The

release behavior shown by the nanocomposite could be suitable for a high dose in an initial stage,

followed by a sustained release. These results show that release behavior of drug-loaded nanocomposite

sample highly is dependent with pH and temperature of body fluid.

[1].K.E. Uhrich, S.M. Cannizzaro, R.S. Langer, K.M. Shakesheff, polymeric systems for controlled drug

release, chem.. Rev. 99 (1999) 3181-3198.

[2]. M. Vallet-Reg1, A. Ramila, R.P. del Real, J. Perez-Pariente, Chem. Mater. 13 (2001) 308. [3]. C.A. Aerts, e. Verraedt, A. Depla, L. Follens, L. Froyen, J. Van Humbeeck, P. Augustijns, International Journal of Pharmaceutics. 397 (2010) 84-91. [4]. P. Horcajada, C. Marquez-Alvarez, A.Ramila, J. Perez-Pariente, M. Vallet-Reg1, Solid State Sciences. 8 (2006) 1459-1465. [5]. G.N.O.HaendelBusatti,E.D.Andrea,etal.,Parasitol.Res.102(2007)145.


Zeolite Molecular Sieve catalyzed Biginelli reaction. One-pot synthesis of

dihydropyrimidinones in both solvent free reflux condition and microwave irradiation

Kaveh Khosravi,a Samira kazemib

a Department of Chemistry, Faculty of Science, Arak University, Zip Cod 38156 - 879 Arak, Iran

bTehran Shahid tondgoyan Oil Refinery Company, Qom Road, Zip code 1879913111, Tehran, Iran

* Tel: +98(0861)2777400 – 4, Fax: +98(0861) 2774031, E-mail: [email protected]

1.Introduction: It is well known that 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) and related compounds

exhibit a wide range of biological activities1 such as antiviral, antitumor, antibacterial and antiflammatory properties. In addition, some of them have been successfully used as the calcium channel blockers, antihypertensive agents and α1a-antagonists.2 Several alkaloids isolated from marine sources also exhibit interesting biological activities, whose molecular structures contain the dihydropyrimidinone unit.3

The simple and direct method for the synthesis of DHPMs reported by Biginelli in 1893 involves the one-pot condensation of an aldehyde, a β-ketoester and a urea under strongly acidic conditions. However, this method suffers from low yields (20–50%) of products especially in the cases of aliphatic and some substituted aromatic aldehydes.4 Recently, new methodologies have been used to improve yields and to decrease time of reaction and to avoid of harsh condition. During the last decade, several efficient methods based on metal-catalyzed Biginelli reaction have been reported. Among the simple metal (and ammonium) salts with nucleophilic anions, e.g. LiBr, NH4Cl, NiCl2.6H2O, FeCl3.6H2O, CuCl2.2H2O, CeCl3.7H2O, Mn(OAc)3.2H2O, ZrCl4, InCl3, InBr3, ZnCl2, ZnI2, CdCl2, BiCl3

are active catalysts. 5 In continues of our works in synthesis of different heterocycles, we have found that the

Zeolite molecular sieve (3A) also is an effective catalyst for this synthesis in both free solvent condition and in microwave irradiation (Scheme 1). Remarkable advantages have obtained in this method. In fact, products were obtained in high yield (65-93%) and good purity and times for completion of these reactions are acceptable (120-250 minutes in solvent free reflux condition and 2.5-6 minutes in microwave condition).

R2O

O O

+H2N

O

NH2

R1= Alkyl and arylR2= Alkyl

Molecular Sieve (3 A)R1CHO +

NH

NHR2O

O

O

R1

Reflux in solvent free conditionor microwave irradiation

Scheme 1

2.Experimental

All the chemicals were purchased from Merck Company. Melting points were measured by using the capillary tube method with an electro thermal 9200 apparatus. 1H and 13C NMR spectra were recorded on a Varian JEOL FX 90 MHz spectrometer (DMSO-d6 solution). IR spectra were run from KBr disk on a PerkinElmer GX FT-IR spectrometer.

General procedure for the synthesis of DHPMs in solvent free condition: A solution of ethylacetoacetate (1.27 ml, 30mmol), aldehyde (10 mmol), urea (1.2gr, 20

mmol), zeolite molecular sieve (3 A, 0.5 g) was heated in reflux condition for appropriate time. The progress of reaction monitored by TLC chromatography. After completion of the reaction,


the reaction mixture was filtrated and then cooled and poured into 50 g of crushed ice and stirring was continued for few minutes. The solid products were filtered, washed with cold water (2×50 ml) and recrystallized from ethanol. All the products are known compounds which were characterized by their IR, 1H and 13C NMR spectral data and their m.ps compared with literature reported mps. General procedure for the synthesis of DHPMs in microwave irradiation: A mixture of urea (0.12gr, 2 mmol), zeolite molecular sieve (3 A, 0.1 g)and aldehyde (1 mmol) dissolved in ethylacetoacetate (0.085 ml, 2mmol) was capped and irradiated in a Milstone Combi Chem Microwave Synthesizer for the appropriate time (Table 2). The progress of the reaction was monitored by intermittent rapid cooling of the mixture to room temperature every one minute and analyzing by TLC (n-hexane/acetone, 2:8). After complete conversion of the substrate as indicated by TLC analysis, the reaction mixture has been solved in hot ethanol (5 ml) and filtrated and then cooled and poured into 10 g of crushed ice and stirring was continued for few minutes. The solid products were filtered, washed with cold water (2×50 ml) and recrystallized from ethanol. All the products are known compounds which were characterized by their IR, 1H and 13C NMR spectral data and their mps compared with literature reported mps.


We started to study the three component Biginelli condensation catalyzed by zeolite molecular sieve (3 A) by examining the conditions for the reaction involving benzaldehyde, urea and ethylacetoacetate to afford the DHPM 1(scheme 2).

RO

O O

+H2N

O

NH2

R= Me or Et

Molecular Sieve (3 A)PhCHO +

NH

NH

Ph

RO

O

OReflux in solvent free conditionor microwave irradiation

Scheme 2 1 The sum of these results clearly indicates that the zeolite molecular sieve (3 A) is equally

efficient catalyst in the Biginelly condensation reaction. The times and purity of product of reaction in microwave irradiation are shorter than solvent free condition but the yields of reactions in solvent free condition are better than yields of reaction in microwave irradiation.

References

[1] C.O. Kappe, Tetrahedron, 49 (1993) 6937 and references cited therein. [2] C.O. Kappe, W. M. F. Fabian, Tetrahedron, 53 (1997) 2803. [3] B. C. Ranu, A. Hajra, U. Jana, J. Org. Chem., 65 (2000), 65, 6270. [4] P. Biginelly, Gazz. Chim. Ital. 23 (1893) 360. [5] D. S. Bose, R. K. Kumar, L. Fatima, Synlett (2004) 279. [6] D. Azarifar, K. Khosravi, Z. Najminejad, Kh. Soleimani, Heterocycles 81 (2010) 81, 2855. [7] D. Azarifar, K. Khosravi, R. Ali Veisi, Arkivoc ix(2010) 178. [8] D. Azarifar, K. Khosravi, J. Chin. Chem. Soc. 56 (2009) 43. [9] K. Khosravi, S. Kazemi, Chin. Chem. Lett. 23 (2012) 23, 61. [10] K. Khosravi, S. Kazemi, J. Chin. Chem. Soc. 59 (2012) in press.


Photodegradation of dyein a batch photoreactor using Ag2S nanoparticles supported

molecular sieves nanoparticles

AfshinPourahmad*

Department of Chemistry, Rasht Branch, Islamic AzadUniversity, Rasht, Iran, [email protected]

1.Introduction The treatment of industrial wastewaters for removing organic pollutants is nowadays a very important aspect of environmental technology. Consequently a growing interest in heterogeneous photocatalysis, as an advanced oxidation technique, has been developed. Synthesis, properties and application potential of semiconductor nanoparticles manifesting photocatalytic activity in various redox-processes have been and the subject of great interest to the present day [1]. Ag2S is a direct, narrow band-gap semiconductor with good chemical stability and excellent optical limiting properties. As the sizes decrease to nano-scale, semiconductor particles will present new physical and chemical properties that cannot be attained with bulk. However, the quantum-sized clusters or particles are not stable. The high surface energy will impel the clusters or nanoparticles to aggregate. Using the well-defined micro cavities of zeolites, it will be possible to control the nanoparticles size of semiconductors. Silver sulfide could be highly dispersed in zeolites and show unique photoluminescence properties. In this investigation Ag2S semiconductor incorporated in MCM-41 nanoparticles by ion exchange method. There is low reports about using Ag ion and silver sulfide semiconductor in mesoporous materials. All of the materials were characterized by various physicochemical techniques. The activity of Ag2S/MCM-41 catalysts for the degradation of methylene blue was study in the presence of UV light.

2.Experimental Nano-sized mesoporous MCM-41 silica with particle size ~ 90 nm was synthesized with some modification to the procedure described in the literature [2]. Synthesis of Ag2S/MCM-41 nanocomposite As a precursor of Ag2S semiconductors, solution of AgNO3 (0.1 mol l-1) was prepared. To 50 ml of AgNO3 solution, 1 g of MCM-41 powder was added and the mixture stirred for 12 h at 25 ºC. The sample was then washed to remove nonexchanged Ag+ and air-dried. Finally, sulphurizing of the Ag+ ions was carried out with 0.1 M Na2S solution. To make the reaction with the S2- ion, one g Ag+ - exchanged zeolite was added to 50 mL of 0.1 M solution of Na2S at a fixed temperature and magnetically stirred for 2 h. Samples were washed with deionized water and collected by filtration. The obtained samples were in fine grey colored powder form. The samples were stable at ambient condition. Photocatalytic degradation experiments Photodegrdation experiments were performed with a photocatalytic reactor system. This bench – scale system consisted of cylindrical Pyrex – glass cell with 1.0 L capacity, 10cm inside diameter and 15cm height. A UV lamp was placed in a 5 cm diameter quartz tube with one end tightly sealed by a Teflon stop the lamp and the tube were then immersed in the photoreactor cell with a light path of 3.0 cm. The photoreactor was filled with 25 ml of 0.16 - 3.2 ppm of dye as pollutant and 0.02-5.00 g/L of Ag2S/MCM-41 as nanophotocatalyst. The whole reactor was cooled with a water–cooled jacket on its outside and the temperature was kept at 25 C .All reactants in the reactions were stirred using a ˚magnetic stirrer to ensure that the suspension of the catalyst was uniform during the course of the reaction. To determine the percent of destruction of dyes, the samples were collected at regular intervals, and centrifuged to remove the nanocatalyst particles that exist as undissolved particles in the samples.

Characterization


X-ray diffraction (XRD) pattern was recorded on a Seisert Argon 3003 PTC. The UV-vis diffused reflectance spectra (UV-vis DRS) were obtained from UV-visScinco 4100 spectrometer. UV-vis absorption spectra were recorded using a Shimadzu 1600 pc in the spectral range of 190-900nm. Transmission electron microscopy (TEM) was performed on a Philips CM10 and microscope operated at 100 kV. Scanning electron microscopy (SEM) images of fabricated Ag2S nanoparticles were obtained using LEO 440i electron microscope. The specific surface area and pore volume of the samples were calculated according to the Brunauer-Emmett-Teller (BET) method. Infrared spectra on KBr pellet were measured on a Bruek spectrophotometer.

3.Results and Discussion The purpose of the present study was to investigate whether the degradation of methylene blue might occur when catalyzed by Ag2S semiconductor nanoparticles in aqueous solution. We can summarize the results as follows. - The ion exchange method is an effective method for support of Ag2S on MCM-41 nanoparticles. - A photocatalyst containing 20 wt% Ag2S has the maximum efficiency on photodegradation of methylene blue. - An U-shaped change in the concentration of methylene blue in the presence of Ag2S was observed along with the change in pH value from 3 to 12.The highest degradation ratio was observed at around pH 8. - The kinetics of photocatalytic degradation of dye is of the pseudo-first order with k= 0.0343. - Ag2S/MCM-41 can be used as an efficient photocatalyst for degradation of dyes under UV light irradiation. References [1] A. Pourahmad, Sh. Sohrabnezhad, E. Kashefian, Spectrochim. Acta, Part A 77 (2010) 1108-1114. [2] Sh. Sohrabnezhad, A. Pourahmad, Spectrochim. Acta, Part A. 86 (2012) 271-275.

Transmission electron microscopy (TEM) image of Ag2S/MCM-41.

(a) X-ray diffraction patterns of MCM-41 and Ag2S/MCM-41 in range 2θ = 2-10º and (b) X-ray diffraction patterns of MCM-41 and Ag2S/MCM-41 in range 2θ = 20-60º.

t = 0

t = 20

Spectra change that occur during the photocatalytic degradation of aqueous solution of methylene blue: pH = 7, [20 wt% Ag2S/MCM-41] = 0.6 g/L, Co = 0.32 ppm.


Zeolite-Based Microsensors for gas sensing (A Review)

Mohsen Mehdipourghazia,*, Narjes Keramatib

a School of Chemical, Petroleum and Gas Engineering, Semnan University, Semnan, 35131-19111, Iran b Department of Chemical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Iran

*Corresponding author, +982313366922, [email protected]

1. Introduction

The development of devices for monitoring of selected chemical components in samples and environments is a major goal in analytical science. Chemical microsensors play an expanding role in the fields of environmental and industries. Zeolites have increasing sensitivity and selectivity and used on a variety of chemical sensors (both reactive and nonreactive). Moreover, zeolites have high thermal stability and chemical resistance and modify the surface of conventional chemical electrodes and consequently, increase their electroanalytical performance [1], as shown in figure1. Chemical microsensors have molecular sieving effects and also selective surface interactions. For example, Zeolite-composite thin films located on the active areas of piezoelectric sensor devices (quartz crystal microbalances). 2. Experimental The regular array of micropores in zeolites effectively control molecular access to the device and allow it to sense ethanol (zeolite MFI), humidity (zeolite LTA and BEA), NO, SO2, and water (zeolite A, silicalite-1, and sodalite) and also for sensing of O2, CO, CO2, NH3, H2, Amines, Hydrocarbons and Organic molecules [3, 4].

Fig.1. SEM images of cross section of a commercial optical fiber coated with a NaA zeolite thick layer,

(a) Total cross section and (b) Magnification view of the NaA zeolite layer [2] 3. Results and discussion

Surface acoustic wave (SAW) devices have a single-crystal quartz substrate with interdigital transducer.

It can operate as highly sensitive piezoelectric balances and respond to small fractions of gas adsorption on a single-crystal monolayer. The application of zeolite coatings (H-ZSM-5, zeolite Y) on SAW devices is applied for humidity and vapor sensing (such as methanol). Also selectivity can be enhanced by tailoring the surface and interfacial interactions of zeolite coatings with silane coupling agents [5, 6].

Cantilevers used as nanoscale sensors for AFM as a surface imaging tool. Standard cantilevers are theoretically capable of detecting a minimum mass loading of 50 fg enabling short response time (milliseconds). ZSM-5 crystals (around 500 ng) have been chemically anchored for humidity and freon-12 sensing purposes, achieving a favorable performance in determining mass loadings at the nanogram scale [7].


Optical sensors have been used for the continuous and real-time monitoring of diverse analytes. A wide variety of satisfactory properties for chromo-phores embedded in inorganic molecular sieves can be expected based on their peculiar host–guest interactions. Molecular-sieve encapsulated dye molecules are recently attracting increasing attention with respect to new photonic devices and optical sensor applications due to an increased light durability, migration stability, and photo degradation resistance with respect to their organic counterparts [8]. Also, the encapsulation of the solvate-chromic dye Nile red inside the pores of dealuminated zeolite Y for optical sensing of acetone and ethanol using spectral absorbance in the UV–VIS range has been reported [9].

Since the adsorption of a gas is able to modify the dielectric constant of zeolites, chemical sensors based on inter digital capacitors (IDCs) using zeolites layers as sensitive coatings offer a wide field of applications depending on the type, modification, and working temperature of the coated IDC sensor. Thus, zeolite-coated IDCs have been tested for sensing n-butane and also, NH3, NO, and CO on Na–Y and Na-Pt-Y zeolite-based sensors at temperatures high enough to where chemical reactions may also occur (above 200°C) [10].

Zeolite barriers have been used as a means of increasing the selectivity of optical and semiconductor–gas sensors. Nishida used commercial crystals of FAU and FER zeolites with colloidal silica as a binder to cover the sensing layer of La2O3–Au/SnO2 sensors. This sensor obtained ethanol filtering effects and increased CO selectivity. Also, he reported the modified semiconductor sensors by mechanically mixing MCM-41 with powdered SnO2 that enhanced H2 sensitivity [11]. 2. Conclusions

The zeolite-based microsensors for gas sensing have received great attention. Zeolites High selectivity for a specific gas, enhance the gas sensing. The compound or cluster sensing towards a gas assembled into the cages or channels of zeolites results in its high stability, and maximally elevate the sensing property of the materials. The application of composite materials partially composed of a zeolite, opens novel ways for choosing gas sensor materials as well. Overall, we predict that zeolites will become widely available materials for gas sensing in the future. References [1] Walcarius. A, Zeolite-modified electrodes in electroanalytical chemistry, Analytica Chimica Acta, 384 (1), 1999, 1–16. [2] López. J, et al, A novel optical device for gas sensor applications based on zeolitic materials, Books of abstracts of the 1st NanoSpain Workshop, San Sebastian, 2004. [3] Yan. Y, Bein. T, Molecular-sieve sensors for selective ethanol detection, Chemistry of Materials, 4(5), 1992, 975–977. [4] Mintova. S, Bein. T, Nanosized zeolite films for vapor-sensing applications, Microporous and Mesoporous materials, 50, 2001, 159–166. [5] Bein T, et al, Molecular-sieve sensors for selective detection at the nanogram level, Journal of American Chemistry Society, 111 (19), 1989, 7640–7641. [6] Yan. Y, Bein. T, Molecular recognition on acoustic wave devices: Zeolite thin films coated with organo silane gate layers, Microporous and Mesoporous materials, 1, 1993, 413–422. [7] Berger R, et al, Micromechanics: A toolbox for femtoscale science: ‘Towards a laboratory on a tip’ Microelectron Engineering, 35(1-4), 1997, 373–379. [8] Calzaferri G, etal, Host–guest antenna materials, Angewandte Chemie, 42, 2003, 3732–3758. [9] Meinershagen. J.L and Bein T. ‘Optical sensing in nanopores.Encapsulation of the solvatochromic dye Nile red in zeolites, Journal of American Chemistry Society, 121(2), 1999, 448–449. [10] Plog C et al, Impedance of zeolite-based gas sensors, Sensors and Actuators B, 25(1–3), 1995, 653–656. [11] Fukui K and Nishida S, CO gas sensor based on Au-La2O3 added SnO2 ceramics with siliceous zeolite coat, Sensors and Actuators B, 45(2), 1997, 101–106.


Laponite RD as Crosslinker to Synthesize Carrageenan-based Nanocomposites

Gholam Reza Mahdavinia1, Abdolhossein Massoudi2, Ali Baghban2, Bakhshali Massoumi2 1Department of Chemistry, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran

2Department of Chemistry, PayameNoorUniversity, P.O.Box19395-3697, Tehran, Iran

*Corresponding: [email protected], Phone: +98-421-2273068, Fax: +98-421-227-3068 1.Introduction Hydrogels are hydrophilic polymer networks that can absorb a large amount of water from aqueous solutions without dissolving. These networks can synthesize through chemical or physical crosslinking. In the case of chemical crosslinking, an appropriate organic crosslinker such as methylenebisacrylamide can be used and the polymer chains will connect to each other by covalent bonds. Recently, nanocomposite hydrogels have been synthesized using different nanoclays. Among them, the hydrogels containing laponitenanoclay has attracted the attention of researchers. Haraguchi et al have reported the synthesis of nanocomposite hydrogels without using organic crosslinkers. They have used laponitenanoclay as multifunctional crosslinker. The ionic and polar interactions at the clay-polymer interface will cause physical crosslinks formation. In fact, by applying laponitenanoclay into hydrogels composition, not only the physical and chemical properties of hydrogels can improve, but also physical crosslinking can occur without using chemical crosslinkers. 2.Experimental In general, laponite was dispersed in 30 mL of distilled water and stirred under magnetic stirrer for 5 h. Dispersed clay solution was transferred to a one-liter reactor equipped with mechanical stirrer. To control the reaction temperature, the reactor was placed in a water bath preset at 60 oC. Then, carrageenan was added to the solution containing clay and stirred until completion of dissolution. AAm was added into the solution and allowed to stir for 1 h. Finally, APS (0.05 g in 2 mL of water) was added as initiator into solution and stirred for 3 min. After this time, the solution was transferred into a test tube and was kept in an oven at 60 oC for 3 days. The nanocomposite hydrogels were cooled and dried for 7 days. 3.Results and Discussions Nanocomposite hydrogels based on carrageenan were synthesized using solution polymerization. Acrylamide and Laponite RD were used as monomer and nanoclaycrosslinker, respectively. The polymerization was carried out using APS initiator. Polymerization of acrylamide will be initiated in the presence of sulfate anion-radical. When polymerization is carried out, the produced PAAm will capture in the laponite layers. The carrageenan biopolymer can not intercalate into laponite layers because of its anionic character. But, it will be captured between PAAm and laponite networks and subsequent a semi-IPN nanocomposite hydrogel will be formed. The XRD patterns of pristine laponite RD and nanocomposites were studied at 2θ=2.5-15° and are illustrated in Figure 1. According to data, the XRD profile of pristine laponite (Figure 1a) shows a broad peak from 2θ=2.5 to 2θ=9.1 with a diffraction peak at about 2θ=4.32 corresponding to the distance of clay sheets with d spacing 20.4 Aº. Stirring of laponite for 5 h subsequently in situ polymerization of AAm in the presence of carrageenan biopolymer leads to nanocomposite hydrogels that the XRD profile of the samples shown in Figure 1b and c. No diffraction peak was observed in nanocomposites and it can be concluded that the clay layers are completely exfoliated. The results indicate that the clay content up to 12.5 wt% of clay can not influence the type of dispersion of


nanoclay in nanocomposite matrix. The SEM micrographs of nanocomposite and clay-free hydrogels were shown in Figure 2 and the surfaces of both samples are smooth.

Figure 1 XRD patterns of pristine clay and nanocomposites

Figure 2 SEM micrographs of clay-free hydrogel and nanocomposite

Although laponite acts as crosslinker, the results revealed that the swelling capacity was enhanced by increasing the clay content from 2.7 to 12.5 wt% of laponite (Figure 3). At 12.5 wt% of clay, maximum water uptake was obtained (307 g g-1). The corresponding increase in swellingup to 12.5 wt% of laponite could be attributed to the increase in ionic osmotic pressure of nanocomposites. Decrease in swelling capacity beyond 12.5 wt% of laponite can be ascribed to the increase in crosslink density and subsequent the swelling. According to the results, the gel content of nanocomposite is decreased after 12.5 wt% of laponite. While the gel content for Clay12.5 is 97 wt%, it is 85 wt% for Clay17.6. By decreasing the gel content, swelling capacity will be decreased.

Figure 3 Effect of nanoclay on the water absorbency and gel content of nanocomposites

References


[1] C. Chang, L. Zhang CarbohydPolym 84 (2011) 40 [2] K.HaraguchiCurrOpin Solid St M 11(2007) 47

Use of Natural Zeolite in Sustainable Agriculture

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