Robust construction of a graphene oxide barrier layer on a nanofibrous substrate assisted by the flexible poly(vinylalcohol) for efficient pervaporation desalination

Here, a novel thin-film nanofibrous composite (TFNC) membrane consisting of an electrospun polyacrylonitrile (PAN) nanofibrous substrate and a robust graphene oxide barrier layer was developed through a facile vacuum filtration method for pervaporation desalination application. The exfoliated hydrophilic graphene oxide (GO) nanosheets were sturdily integrated together onto the PAN nanofibrous support with the aid of a flexible connector poly(vinylalcohol) (PVA) and a crosslinking agent glutaraldehyde (GA) via vacuum filtration. The hydrophilic PVA chains acting as the spacing bridges ensured that the stacked GO nanosheets were interlinked successfully with sufficient bonding by GA to provide adequate stability in a water environment. Benefiting from the superiority of an ultra-thin hydrophilic peculiar GO skin layer and a fully interconnected porous nanofibrous substrate, the resultant optimized robust GO/PAN TFNC membranes displayed an excellent permeate flux of 69.1 L m(-2) h(-1) and a stable high rejection (99.9%) over a testing period of 24 h from aqueous salt solution with NaCl concentrations of 35 g L-1 at 70 degrees C. This separation performance was superior to those of homogeneous membranes and composite membranes used in pervaporation desalination reported so far, indicating that this work may facilitate the development of pervaporation in practical desalination application.