Effect of crosslinker 3-methacryloxypropylmethyldimethoxysilane on UV-crosslinked PDMS-PTFPMS block copolymer membranes for ethanol pervaporation

Crosslinker vital factor for the preparation of polymeric membranes, which has a substantial effect not only on the membrane-forming process, but also on the membrane structure as well as separation performance. However, little attention has been paid on UV-crosslinked membrane for organics pervaporation. In this work, the effect of crosslinker 3-methacryloxypropylmethyldimethoxysilane (KH571) on (1) the UV-crosslinking kinetics was characterized by real-time infrared spectroscopy and photo-rheology, (2) the membrane structure was characterized by crosslinking density, and (3) separation performance was evaluated by ethanol pervaporation. Moreover, the conventional polydimethylsiloxane(PDMS) was replaced by polydimethylsiloxane-poly[(3,3,3-trifluoropropyl)methylsiloxane] (PDMS-PTFPMS) block copolymer, where the strong C-F bond contributes to enhance membrane hydrophobicity. Results show an ultrafast membrane-forming process (30-50s) for all coating solution systems and an outstanding separation performance, including 11.3 of ethanol separation factor and 1149 g m(-2)h(-1) of total flux for pervaporation recovery of 5 wt% ethanol/water solution at 60 degrees C. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

The study focused on the effect of crosslinker KH571 on UV-crosslinking kinetics, membrane structure, and ethanol pervaporation separation performance. Replacing conventional PDMS with PDMS-PTFPMS block copolymer led to a fast membrane-forming process and excellent separation performance, with an ethanol separation factor of 11.3 and a total flux of 1149 g m(-2)h(-1) achieved.