A facile approach for the development of fine-tuned self-standing graphene oxide membranes and their gas and vapor separation performance

A detailed study of the gas permeance properties of self-standing graphene oxide (denoted hereafter as GO) membranes, in relation to their pore structure characteristics and their surface chemistry, are reported herein. By varying the filtration rate of the starting GO suspension as well as the amount of the surface functional groups of the employed GO, it was possible to fine tune the pore size of the developed GO membranes. The involved filtration approach led to the arrangement of the two-dimensional GO stacks/layers on the top surface of mixed cellulose ester (MCE) filters with pores of 0.45μm. The as-produced films (7–20μm thick GO membranes) were easily detached from the MCE substrate and could be incorporated in a membrane module for performing gas permeability studies. Gas transport through the void space between GO stacks, or discontinuities of GO layers, was dominant over transport through the inter-layer space.