Preparation of PVA-PFSA-Si pervaporative hybrid membrane and its dehydration performance

Abstract

In order to ameliorate the trade-off effect in pervaporation process and to reduce the micro-phase separation of hybrid membrane, polyvinyl alcohol (PVA)-perfluorosulfonic acid (PFSA) blending materials were modified by two inorganic components to prepare PVA-PFSA-Si hybrid membrane. PVA-PFSA-Si membrane was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurements, scanning electron microscopy (SEM), positron annihilation lifetime spectrometer (PALS) and swelling measurements. As a second inorganic modifier, the effect of γ-glycidyloxypropyl trimethoxysilane (GPTMS) on the morphology of hybrid membrane was better than that of γ-aminopropyl triethoxysilane (APTEOS). PVA-PFSA-Si/polyacrylonitrile (PAN) composite membrane was used to pervaporatively dehydrate ethyl acetate (EAc)/H2O binary, EAc/ethanol (EtOH)/H2O ternary EAc/acetic acid (HAc)/EtOH/H2O quaternary solutions. At feed temperature of 40 °C, M8 membrane had the permeation fluxes (J) of 262.7, 215.2 and 182.6 g m−2 h−1 and the separation factors (α) of 6673, 3453 and 5374 for pervaporative dehydration of EAc/H2O (98/2, wt%) binary, EAc/EtOH/H2O (96/2/2, wt%) ternary and EAc/HAc/EtOH/H2O (96/1/1/2, wt%) quaternary solutions, respectively. The pervaporative results showed that PVA-PFSA-Si membrane had the excellent dehydration performances for EAc binary or multicomponent aqueous solutions.