Dicarboxylic acids crosslinked graphene oxide membranes for salt solution permeation

•Graphene oxide membranes were covalently crosslinked by dicarboxylic acids.•The pyrolysis temperature of crosslinked membranes increased while the swelling degree decreased.•The fluxes of single salt solutions are positively correlated to swelling degree of GO membranes.

Graphene oxide (GO) membranes were crosslinked by dicarboxylic acids in order to improve the mechanical strength, stability and permeation performance. The effects of crosslinking conditions (temperature, catalyst concentration, time, crosslinker concentration) on the mechanical performance, along with the influences of crosslinker molecular structure on the thermal stability and swelling degree of GO membranes, were studied. The thermal pyrolysis temperature of crosslinked GO membranes increased about 2–8 °C while the swelling degree averagely decreased about 66% in DI water and 40% in 0.05 mol L−1 of KCl solution in comparison with those of pristine one. In the permeation of single salt solutions, the fluxes are positively correlated to the swelling degree of GO membranes. The effects of swelling degree on the permeation fluxes were firstly noticed. The crosslinked GO membranes show high permeation fluxes (more than 2 times) along with low swelling degree, demonstrating its potential application in ion dialysis.

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