Fig. 3: Boosted permeance and selectivity of the NIGMs for CO2 separation.

a Schematic illustration of GMs, NIGMs and pure gel covered NIGMs. b Cross-sectional images of GMs, NIGMs and pure gel covered NIGMs and their associated gel layer thickness. c CO2 permeance and d CO2/N2 selectivity of GMs, NIGMs and pure gel covered NIGMs. e Comparison of the NIGMs and reported MMMs in terms of the improvement of CO2 permeability and CO2/N2 selectivity.