Organic Solvent Permeation through Negatively Charged Graphene Oxide Membranes

Abstract

Graphene oxide (GO) has emerged as a promising membrane material for organic solvent nanofiltration. This study aims to understand the permeation behaviors of five polar organic solvents [namely, methanol, isopropyl alcohol (IPA), dimethyl sulfoxide (DMSO), acetone, and methyl tert-butyl ether (MTBE)] through negatively charged GO membranes, benchmarked against that of water. Among the solvents studied, water exhibits the highest permeation rate. Among the protic solvents (namely, water, methanol, and IPA), permeation decreases in the order of increasing molecular size and decreasing polarity. As for the aprotic solvents, acetone has the highest permeability due to the lowest viscosity and the smallest molecular size. The C atom of graphene in the GO membrane facilitates solvent flow because of weak interactions with the solvent molecules. Overall, the results exhibit that solvent permeation is governed by molecular size, viscosity, and membrane–solvent interactions. The findings from the study are expected to be valuable in the design of GO-based membranes for organic solvent nanofiltration.