Phase-Transition Ionic Liquid Endows COF-Based Mixed Matrix Membranes with Efficient CO2 Separation

Abstract

The interfacial compatibility of COF-based MMMs was significantly enhanced through the incorporation of thermoresponsive phase-transition ionic liquid. The IL@DAAQ-COF is synthesized in situ and the IL plays a key role in cutting the COF channel and enhancing the CO2 affinity. The resultant membrane exhibited a CO2 permeability of 17,449 Barrer and a CO2/N2 separation selectivity of 27.2, which broke through the 2019 Jansen/McKeown upper bound. This study highlights the important role of IL and thermal treatment in improving the performance of gas separation membranes.