Synthesis and gas permselectivity of CuBTC–GO–PVDF mixed matrix membranes

Abstract

A CuBTC (copper(II) benzene-1,3,5-tricarboxylate) metal organic framework (MOF) and graphene oxide (GO) nanosheets were introduced into a semi-crystalline PVDF to produce mixed matrix membranes (MMMs) to promote gas separation performance. CuBTC/GO co-existence in PVDF exhibited positive effects on thermal, mechanical, and permselectivity properties of MMMs. While MMMs owed their higher permeabilities to porous CuBTC particles, GO nanosheets were mostly responsible for induction of remarkable selectivity into the PVDF matrix. The best gas separation was reported for a MMM with 9.5/0.5 wt% of CuBTC/GO. In this regard, He and CO₂ permeabilities of 10.066 and 3.316 barrer were obtained accompanied by more than 100% increases in He/CH₄, He/N₂, and CO₂/CH₄ gas selectivities. Homogenous dispersion of fillers, filler morphologies, and well polymer/filler interactions are responsible for such interesting behavior.