Insect-Inspired Strategy for Conferring Reversible, High Responsivity on Microgels to Dilute-Source CO₂

We described an insect-inspired strategyfor conferring reversible,high responsivity on polymer microgels to dilute-source CO2 (<= 5000 ppm in gas mixtures). This is demonstrated on oligo(ethyleneoxide)-based microgels that contain tertiary amines on the polymerchains with proper organic small molecular carbonates in the polymer-solventsystem. Similar to the synergistic contribution of the CO2 receptor subunits in mosquitoes for CO2 response, laserlight scattering and related studies indicated that the CO2-response of the microgels in terms of the volume changes works throughthe coordination of different functional moieties in the system, makingit different from the conventional CO2-response mechanism.While this pushes the lower response threshold of CO2 concentrationdown to ca. 1000 ppm, this unique strategy can also satisfy the urgeto achieve both effective CO2 capture and facile CO2 release, making it possible to couple the detection withthe capture and utilization of indoor excess CO2.