Bulgarian Chemical Communications, Volume 48, Number 4 (pp. 779 – 786) 2016 779 Effect of modification of Zeolite A using Poly Vinyl Alcohol (PVA) S. K. Rout 1 *,P. Padhi 2 , D.Panda 2 1 Department of Chemistry,Konark Institute of Science & Technology, India 2 Research and Development Center, Hi-Tech Medical College & Hospital, India Received February 12, 2015; Revised April 25, 2016 Structural modification of raw zeolite A was carried out at a temperature of 80°C using low and high Poly Vinyl Alcohol (PVA). The product was characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), High Resolution Transmission Electron Microscopy (HRTEM) and Image Analyzer (IA). XRD shows PVA anchored to the faces [6 0 0], [6 2 2], [6 4 2], [6 4 4] resulting in a НОМrОКsО Тn tСО МrвstКХХТtО sТгО oП tСО ЦoНТПТОН гОoХТtО. But 600°C calcination cannot remove the anchored PVA from the zeolite faces, so calcination does not change the crystallinity. FTIR shows the noise level of the bands in the region 400-420 cm -1 decreased in modified zeolite A indicating the raw zeolite surface is smoothened by the application of PVA. From FESEM it is found that the shape of the modified particles changed to slightly spherical with the reduction in size. EDS confirms the oxygen percentage is increasing whereas the Na, Al, and Si percentages are decreasing after modification. HRTEM shows the modification is prominent for zeolite modified with a high PVA and the particle size is reduced to 1.5µЦ. The particle size analysis shows that after modification with a low and high PVA the maximum particles have the size within the range of 2-2.5 µЦ (2λ % size reduction as compared to raw zeolite A) and 1.5-2 µЦ (43 % sТгО rОНuМtТon Кs МoЦpКrОН to rКа гОoХТtО A) respectively and there was no significant change in particle size after calcination. Keywords: Zeolite A, Poly Vinyl Alcohol (PVA), Ultrasonication, Centrifugation and Calcination. INTRODUCTION Zeoliteis a crystalline hydrated framework of alumino-silicatehaving Рroup I КnН ΙΙ elements,in particular, sodium, potassium, calcium, magnesium, strontium and barium [1, 2].More than 150 synthetic and 40naturally occurring zeolites are known [3].Theycan be represented by the empirical formula M 2/n O.Al 2 O 3 .xSiO 2 .yH 2 O. In this oxide formula, x is generally equal to or greater than 2, since tetrahedral AlO 4 joins only tetrahedral SiO 4 and n is the valency of the cation. Natural zeolites wereused initially for different applications, but more recently modified and synthetic forms have been made on an industrial scale giving rise to tailor made zeolites that are highly replicable. Zeolites are highly crystalline due to the well defined structure and enclose the aluminium silicate framework cavities occupied by large ions and water molecules, with the cavities opening ranging from 0.8-1.0 nm in diameter which are the order of the molecular dimensions. The size and shape of these pores determine which molecules enter the cavities and which are excluded. These are called molecular sieves [4]. Cations within the cavities are easily replaced with a large number of different valencycations which exert large electrostatic forces across the small dimension of the cavity, while the introduced cations have separate activities of their own; this facilitates dual function catalysis involving acidity along with other activities [4]. The chemical formula of zeolite A is Na 12 [AlO 2 .SiO 2 ] 12 .27H 2 O. According to the data base for zeolite structure [5], zeolites of type A are classified into three dimensional grades, 3A, 4A and 5A, all of which possess the same general formula but with a different cation type. Zeoliteis commercially produced from sodium aluminate and silicate by hydro gel processes [6]. Faujasite zeolites are obtained from KanKara Kaolin clay [7] and zeolite NaX was synthesized from Kerala Kaolin [8]. Because of the presence of a large volume of micro pores and the high thermal stability of the zeolite, this material is used for purification of waste water, and soil remediation [9- 10]. Synthetic zeolites are widely used as industrial adsorbents for various gases and vapours [8] and as catalysts in the petroleum industry [11]. Zeolites have a high tendency to adsorb water and other polar compounds like NH 3 , CO 2 , H 2 S and SO 2 and have a good capacity at very low temperatures compared with other adsorbents. Pressure swing adsorption (PSA) is one of the techniques which can be applied for the removal of CO 2 from gas streams. Zeolite has shown promising results in the separation of CO 2 from gas mixtures and can potentially be used in thePSA process [12-14]. Perfect defect free zeolite crystalline structures are not readily available or easy to prepare. Therefore most of the zeolite material has defects * Towhomall correspondence should be sent: E-mail: sanjay.tulu@gmail.com  2016 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria