Construction of graphene oxide membrane through non-covalent cross-linking by sulfonated cyclodextrin for ultra-permeable butanol dehydration

Abstract

Two-dimensional (2D) lamellar graphene oxide (GO) membranes represent promising porous materials in alcohol dehydration. The separation performance can be manipulated by the physicochemical properties of interlayer channels. The relatively low flux and poor stability of GO-based membranes in aqueous environment are the major drawbacks. Herein, we intercalated a supramolecular compound, sulfobutyl-β-cyclodextrin (SCD), into the interlayer pores/channels of GO membranes. The sulfonic acid groups on SCD molecules are able to cross-link adjacent GO nanosheets throughnon-covalent interactions. The GO-SCD membranes possess excellent water affinity due to the presence of high hydrophilic sulfonic acid groups. For the n-butanol dehydration, the GO-SCD/PTFE membranes with well-defined interlayer pores exhibited ultrahigh permeation flux of 12955 g m-2 h-1 and separation factor of 1299 under 80 oC. The membranes remained stable in 144 h separation performance evaluation test and exhibited obviously enhanced thermal stability.