Preparation of Sodium Montmorillonite Clay Loaded Poly(Vinyl Alcohol)-Chitosan Composite Mixed Matrix Membranes and Their Application in Pervaporation Dehydration of Isopropanol

By : Hemang R. Mehta, Z.V.P. Murthy

Page No: 319-331

Abstract
Isopropanol-water system was separated by pervaporation using poly(vinyl alcohol)-chitosan (PVA-CS) / sodium montmorillonite clay (Na+MMT) composite matrix membranes at 50°C. Membranes were prepared by incorporating 0.5 and 1 wt.% of clay particles into PVA-CS composite and then crosslinked it with tetraethoxysilane (TEOS). Membrane morphology and cross-section were characterized by scanning electron microscopy (SEM). Zetasizer was used to determine the Na+ MMT clay particle size. To understand thermal properties of membranes, thermogravimetric analysis (TGA) was used. Separation factor for PVA-CS composite membrane was found to be 27.34, which increased to 47.49 and 61.86 for addition of 0.5 and 1 wt.% clay, respectively. Values of fluxes obtained for separation of 10:90 water-isopropanol (IPA) system was 0.099 kg/ m2 h for 0.5 wt.% clay and 0.093 kg/m2 h for 1 wt.% clay. Membranes were further used for the system that contained water to IPA ratios of 15:85, 20:80, 25:75, 30:70 to ensure that with increase in water fraction in feed, the separation factor decreases and flux increases. Degrees of swelling of membranes were measured for systems with water content ranging from 10:90 to 30:70 water to IPA ratio.

Authors :
Hemang R. Mehta and Z.V.P. Murthy : Department of Chemical Engineering, S. V. National Institute of Technology Surat – 395 007, Gujarat, India