Poly(ether sulfone) supported hybrid poly(vinyl alcohol)–maleic acid–silicone dioxide membranes for the pervaporation separation of ethanol–water mixtures

Microporous poly(ether sulfone) (PES) supported hybrid polymer–inorganic membranes were prepared by the crosslinking of poly(vinyl alcohol) (PVA), maleic acid (MA), and SiO₂ via an aqueous sol–gel route and a solution‐casting method. The membrane performance was tested for the pervaporation separation of ethanol–water mixtures from 20 to 60 °C with a feed ethanol concentration of 96 wt %. The membrane characterization results reveal that different SiO₂ loadings affected the crystallinity and roughness of the membranes. The PVA–MA–SiO₂ membrane containing 10 wt % SiO₂ showed that SiO₂ nanoparticles were well dispersed within the polymer matrix; this resulted in significant enhancements in both the flux and selectivity. The membrane achieved a high water permeability of 1202 g·μm·m^?2 h^?1 kPa^?1 and a selectivity of 1027 for the separation of a 96 wt % ethanol‐containing aqueous solution. This enhanced membrane performance might have been due to the dense crosslinking membrane network, increased free volume, and uniform distribution of SiO₂ nanoparticles. Both the water and ethanol fluxes increased with the feed water concentration and temperature. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44839.