Analogous Mixed Matrix Membranes with Self‐Assembled Interface Pathways

Abstract

AbstractThe implementation of mixed matrix membranes (MMMs) for sub‐angstrom scale gas separations remains a grand challenge. Herein, a series of analogous mixed matrix membrane (AMMMs) were constructed via molecular‐level hybridization by utilizing a reactive ionic liquid (RIL) as the continuous phase and graphene quantum dots (GQD) as nanofiller for sub‐angstrom scale ethylene/ethane (0.416 nm/0.443 nm) separation. With a small number of GQDs (3.5 wt%) embedded in GQD/RIL AMMMs, ethylene permeability soared by 3.1‐fold, and ethylene/ethane selectivity simultaneously boosted by nearly 60 % and reached up to 99.5, which outperformed most previously reported state‐of‐the‐art membranes. Importantly, the interfacial pathway structure was visualized and their self‐assembly mechanism was revealed, where the non‐covalent interactions between RIL and GQDs induced the local arrangement of IL chains to self‐assemble into plenty of compact and superfast interfacial pathways, contributing to the combination of superhigh permeability and selectivity.