Fabrication of pervaporative composite PDMS.MWCNT/PES membrane for ethanol/water separation

Abstract

A dense, thin, and hydrophobic active layer of polydimethylsiloxane (PDMS) on polyethersulfone (PES) along with desired additives such as polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and SiO 2 as support layers was successfully fabricated. The effect of types of support layers on ethanol separation in pervaporation process was investigated. With desired composite PDMS/PES. PVP (having 76% porosity), ethanol separation factor and total flux were 6.25 and 440 g/m 2 . h, respectively. In order to enhance membrane’s ethanol selectivity, specific additives were added; in fact, extra improvements in ethanol separation with novel membrane were performed. To improve the hydrophobicity of the fabricated membrane, multiwalled carbon nanotubes (MWCNT’s) with several weight percentages were added to the active layer of the composite membrane matrix. At desired percentage of MWCNT (3 wt.%) and total flux of 420 g/m 2 . h, the ethanol separation factor was enhanced by 26.4%.