High-flux corrugated PDMS composite membrane fabricated by using nanofiber substrate

Abstract

Polydimethylsiloxane (PDMS) is a benchmarked membrane material for pervaporation, gas separation, and nanofiltration, remaining challenges in achieving high-flux membrane. Herein, we proposed a high-flux PDMS membrane with corrugated morphology realized by simply coating PDMS solution on nanofiber substrate. It was demonstrated that the electrospun nanofiber substrate with highly interconnected and porous structures could generate a corrugated PDMS membrane layer with highly increased surface area and meanwhile remarkably reduce transport resistance of the membrane. By optimizing the pore structure of nanofiber substrate and reducing the membrane thickness to sub-micrometer, the corrugated PDMS membrane exhibited up to one order of magnitude higher permeation flux compared with state-of-the-arts PDMS membranes for pervaporation separation of ethanol/water mixtures. Specifically, using a 5 wt% ethanol/water mixture as feed at 60 °C, a total flux of 8.7 kg m −2 h −1 and a separation factor of 7.2 were obtained. This work provides a facile approach to develop nanostructured membranes with highly enhanced transport properties. ➢ Corrugated membrane surface is created by coating PDMS on nanofiber substrate ➢ Highly porous and interconnected nanofiber substrate reduce transport resistance ➢ Corrugated PDMS/nanofiber membrane show significantly enhanced pervaporation flux