Surface functionalized UiO-66/Pebax-based ultrathin composite hollow fiber gas separation membranes†
Pebax-based composite hollow fibre membranes are promising candidates for industrial gas separation, but their application is limited by the inherent separation performance of the polymeric materials and the poor operational stability especially under elevated pressures. The incorporation of metal–organic frameworks (MOFs) has been extensively investigated as a potential solution to these problems. However, the major challenges are to control the microvoids in the interfacial region and to improve the effective MOF loading within the selective layer. In this work, we applied a zirconium-based rigid MOF (UiO-66) to fabricate a nanocomposite hollow fibre membrane, and (–COOH) and (–NH2) modified UiO-66 were applied to investigate the effect of surface functionalization. Up to 80 wt% UiO-66 was incorporated into the thin Pebax selective layer, and both improved CO2 permeance and selectivity were obtained simultaneously with the (–NH) functionalized UiO-66. In addition, the presence of UiO-66 in Pebax significantly improved the membrane's operational stability under high pressure.