(452c) Ionomers of Intrinsic Microporosity (IonomIMs): In silico Development of Ionic-Functionalized Gas Separation Membranes

This work presents the predictive molecular simulations of a polymer of intrinsic microporosity (PIM) functionalized to contain an ionic backbone with extra-framework counter ions for CO₂ gas storage and separation applications. The introduction of the highly CO₂-phillic carboxylate groups maintain high degrees of free volume from the inefficiently packed polymer chains without filling pore volume, with the surface areas increasing with decreased concentration of ionic groups from 100% to 17%. As a result of the ionic groups increasing the CO₂ enthalpy of adsorption, the uptake of the proposed polymers at 293 K and ambient pressure exceeded previous microporous ladder polymer capacities. In addition, the CO₂/CH₄ and CO₂/N₂ mixed-gas separation performances were evaluated at several industrially-relevant conditions, where the IonomIMs are shown to increase both the working capacity and selection performance in certain pressure swing applications, and outperformed many leading metal organic framework materials. These simulations reveal that intrinsically microporous ionomers show great potential as the future of energy efficient gas separation polymeric materials.