Investigating the influence of sol gel derived PVA/SiO2 nano composite membrane on pervaporation separation of azeotropic mixture I. Effect of operating condition

The novel organic–inorganic membrane was synthesized using biodegradable PVA as polymer and silica by sol–gel derived route for application in pervaporation of binary azeotropic mixture. Tetra ethyl ortho silicate was used as silica precursor, and maleic acid (MA) or glutaraldehyde (GA) is used as the cross linking agent. Characterization results show a decrease in swelling behavior with an increase in silica content due to a more rigid structure. Effects of different silica loading and cross-linking agents (MA/GA) were studied on the performance of the membrane. The chemically cross-linked composite membrane prepared shows improved performance concerning flux and selectivity when compared to the pristine polymeric membrane. Pervaporation experiments were also carried out at different feed concentration, temperature and activation parameter are evaluated using nano composite membrane at which excellent results are obtained. It was concluded that intercalation of silica and cross-linking changes semi-crystalline PVA to an amorphous polymer which favored and facilitate diffusion of the water molecule to permeate out through membrane hence flux increases.