Interactions in Zeolite-Polymer Composites

Interactions in Zeolite-Polymer Composites

Çigdem Atalay-Oral, Þafak Bora, Melkon Tatlier, Department of Chemical Engineering, Istanbul Technical University,Maslak, 34469 Istanbul, Turkey

The preparation of composite materials containing zeolite has already attracted interest for a few applications. Polymer-zeolite mixed matrix membranes were obtained by dispersion of zeolite crystals in polymeric films for use in gas separation and pervaporation. The quality of the interface between zeolite crystals and polymer are key points in related research studies [1]. A few studies also exist concerning the preparation of composite zeolite coatings. Layers of low and high silica zeolites were grown on aluminium substrates [2]. Zeolite coatings prepared on stainless steel were covered by polyacrylic acid [3]. An interesting observation was that composite samples desorbed somewhat higher amounts of water compared to both pure zeolite and pure polyacrylic acid coatings. In this study, the presence of interactions was investigated for different zeolite-polymer and zeolite-zeolite composite coatings.

Zeolite coatings were prepared on stainless steel by using the substrate heating method. Some of the coatings were covered by various polymers, such as polyvinyl acetate, polyvinyl alcohol and cellulose acetate. Composite zeolite A, X, P coatings were prepared by applying two consecutive syntheses, to form two layers of different zeolite types. The coatings were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and thermogravimetry (TG). It was observed that when the zeolite coatings were covered by polymer, they exhibited water desorption of about 0.13-0.15 g/g sample which was higher than the amount of water desorbed from both pure zeolite (0.12-0.14 g/g sample) and pure polymer (0.038-0.083 g/g sample) under the operating conditions. The interactions between the polymer and zeolite phases seemed to be mainly reponsible for this favorable effect. It was possible to prepare composite zeolite coatings with different amounts of zeolite A, X and P phases. TG analyses revealed the adsorption/desorption capacities of the composites without significant interactions.

References

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[2]    R. Munoz, D. Beving, Y. Mao, Y. Yan, Micropor. Mesopor. Mater. 86 (2005) 243.

[3]    A. Atakan, Ç. Atalay-Oral, M. Tatlier, T. Erciyes, A. Erdem-Þenatalar, Micropor. Mesopor. Mater.  

   156 (2012) 262.