Carbon Dioxide Chemically Responsive Switchable Gas Valves with Protonation-Induced Liquid Gating Self-Adaptive Systems.

Carbon dioxide (CO 2 ) capture and storage technologies are promising to limit CO 2 emission from anthropogenic activities, to achieve carbon neutrality goals. CO 2 capture requires one to separate CO 2 from other gases, and therefore a gas flow system that exhibits discernible gating behaviors for CO 2 would be very useful. Here we propose a self-adaptive CO 2 gas valve composed of chemically responsive liquid gating systems. The transmembrane critical pressures of the liquid gate vary upon the presence of CO 2 , due to the superamphiphiles assembled by poly(propylene glycol) bis(2-aminopropyl ether) and oleic acid in gating liquids that are protonated specifically by CO 2 . It is shown that the valve can perform self-adaptive regulation for specific gases and different concentrations of CO 2 . This protonation-induced liquid gating mechanism opens a potential platform for applications of CO 2 separators, detectors, sensors and beyond.