Enhanced flux of polydimethylsiloxane membrane for ethanol permselective pervaporation via incorporation of MIL-53 particles

Metal organic frameworks (MOFs) have received much attention in recent years because of their good compatibility with polymer as well as their porous structure that facilitates transport tillers in a polymer matrix. In this study, MIL-53 particles were synthesized and incorporated into polydimethylsiloxane (PDMS) matrix to produce novel MIL-53/PDMS hybrid membrane. The morphologies and structures of MIL-53 particles and their hybrid membranes were characterized by SEM, XRD, FTIR, AFM and contact angle. It can be seen from the results that MIL-53 particles formed hydrogen bonding with PDMS and dispersed well in PDMS matrix. In addition, the hydrophobicity of hybrid membrane were improved due to the doping of MIL-53 particles. The MIL-53/PDMS hybrid membranes were used for ethanol permselective pervaporation. The effects of particle loading, feed concentration and temperature on the separation performance of MIL-53/PDMS membranes were investigated. The results indicated that compared with pristine PDMS membrane, the permeate flux of MIL-53/PDMS hybrid membranes with 40% loading significantly increased from 1667 to 5467 g/(m(2) h), while the separation factor remained 11.1. The enhancement of the permeate flux could be attributed to the water-repellency surface and ethanol-affinity channels of MIL-53 particles. The unique nature of MIL-53 suggests a promising future to fabricate hybrid membranes for ethanol recovery via pervaporation process. (C) 2015 Elsevier B.V. All rights reserved.