Optimization of a MOF Blended with Modified Polyimide Membrane for High-Performance Gas Separation

The preparation, characterization and gas separation properties of mixed matrix membranes (MMMs) were obtained from polyimide capped with ionic liquid and blended with metal-organic frameworks (MOFs). The synthesized MOF was amine functionalized to produce UiO-66-NH(2), and its amino group has a higher affinity for CO(2). Mixed matrix membranes exhibited good membrane forming ability, heat resistance and mechanical properties. The polyimide membrane exclusively capped by ionic liquid exhibited good permselectivity of 74.1 for CO(2)/CH(4), which was 6.2 times that of the pure polyimide membrane. It is worth noting that MMM blended with UiO-66-NH(2) demonstrated the highest ideal selectivity for CO(2)/CH(4) (95.1) with a CO(2) permeability of 7.61 Barrer, which is close to the 2008 Robeson upper bound. The addition of UiO-66-NH(2) and ionic liquid enhanced the permselectivity of MMMs, which may be one of the promising technologies for high performance CO(2)/CH(4) gas separation.