Effect of Oxidized-Group-Supported Lamellar Distance on Stability of Graphene-Based Membranes in Aqueous Solutions

Abstract

Graphene oxide (GO) membranes with diverse lamellar distances can achieve sieving of molecules of different sizes in aqueous solutions. Without the extra assistance of cross-linking, the increase of lamellar distance supported by self-contained oxidized groups could diminish the internal π–π attraction force of GO membranes, resulting in the instability of GO membranes. However, the critical value of oxidized-group-supported lamellar distance of unstable GO membranes in aqueous solutions, which is crucial in applications for precise sieving of molecules, still remains unknown. In this study, the effect of oxidized-group-supported lamellar distance on the stability of graphene-based membranes in aqueous solutions is systematically investigated. By controlling the content of oxidized groups via changing reducing condition, different lamellar distances of graphene-based membranes are obtained. With changing the lamellar distance in aqueous solutions under different pH conditions, the graphene-based membranes...