Synthesis, characterization and application of PVA/ionic liquid mixed matrix membranes for pervaporation dehydration of isopropanol

In this study, polyvinyl alcohol (PVA)-ionic liquid (IL) membranes were prepared for the separation of isopropyl alcohol (IPA)-water azeotropic mixtures by pervaporation. PVA-IL composite membranes were prepared by simple solvent evaporation method using four ILs, viz., 1-n-butyl-3-methylimidazolium chloride (BMIMCl), 1-hexyl-3-methylimidazolium chloride (HMIMCl), 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF4) and 1-octyl-3-methylimidazolium chloride (OMIMCl). Three ILs were used to study the effect of alkyl chain on the pervaporation performance. The study had focused on the effect feed water concentration from 10%-40% and effect of feed temperature from 50-80 degrees C. Physiochemical properties of all the membranes were studied using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement. The Arrhenius activation energies for permeation were estimated to be in the range 4-12 kJ.mol(-1) from the temperature dependent permeation values. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.