A phase-transition ionic liquid endows COF-based mixed matrix membranes with efficient CO2 separation

The interfacial compatibility of COF-based MMMs was significantly enhanced through the incorporation of thermoresponsive phase-transition ionic liquids. The IL@DAAQ-COF was synthesized in situ, with the ionic liquid (IL) playing a key role in modulating the COF channel and enhancing the CO₂ affinity. The resulting membrane exhibited a CO₂ permeability of 17 449 Barrer and a CO₂/N₂ selectivity of 27.2, surpassing the 2019 Jansen/McKeown upper bound.