Graphdiyne-based integrated membrane for enhanced alcohol-permselective pervaporation

Abstract

Exploring nano-engineered polymeric membrane with a customized architecture is urgent for the advance of alcoholophilic pervaporation. Graphdiyne (GDY) is a promising candidate material for constructing alcohol-permselective membranes due to its unique alkyne-rich framework in terms of well-organized porous system and strong hydrophobicity. Herein, we report a GDY-based integrated membrane composed of a loosened hydrogen-substituted GDY (HsGDY)-polydimethylsiloxane (PDMS) mixed-matrix layer on a polysulfone ultrafiltration support and a moderate pore-filling PDMS crosslinking layer. The procedure for fabricating such an integrated bilayer membrane was implemented by a simple vacuum-assisted filtration followed a dip-coating post-treatment. The resultant HsGDY-based integrated membrane shows a separation factor of 12.8 together with a total flux of 1535.7 g m−2 h−1 in the separation of a 5.0 wt% ethanol-water solution. The overall performance is also competitive among the reported ethanol-permeselective membranes, benefiting from the synergy of alcohol adsorption-preferential permeation processes by the HsGDY-based integrated bilayers. A continuous and long-term pervaporation test indicates the robust operating stability. An enhanced separation performance for other alcohols (C1–C4) suggests the great potential of HsGDY-based integrated membranes for in situ recovery of bioalcohols.