Synergistic effect of hybridized TNT@GO fillers in CTA-based mixed matrix membranes for selective CO2/CH4 separation

Abstract

Titanium dioxide nanotube (TNT) amalgamated graphene oxide (GO) matrix was blended with cellulose triacetate (CTA) polymer to form a new kind of mixed matrix membranes (MMMs) for the selective biogas upgrading. The effect of hybrid fillers on the physico-chemical, thermal and mechanical properties of membranes were studied using different spectroscopic techniques. Notable improvements on these properties were observed on MMMs as compared to the pristine membrane. Similarly, resulting MMMs exhibited higher CO2 adsorption affinity. Furthermore, single gas permeation measurements revealed higher permeability as well as selectivity for [email protected]/CTA membrane. CO2 permeability increased almost 7 times, reaching 22.54 Barrer, whereas CO2/CH4 selectivity increased nearly three folds from 25.06 for the pristine membrane to 86.69 for [email protected]/CTA membrane and reached the Robeson 2008 upper bound. The long term stability experiment of the [email protected]/CTA membrane confirm the anti-aging ability suggesting its practical application in the bio/natural gas upgrading process. These results established an effective modification approach for applying alternative porous hybrid fillers into gas separation applications.