Oxygen and Carbon Dioxide Dual Gas-Switchable Thermoresponsive Homopolymers.

Herein, we report the first oxygen (O) and carbon dioxide (CO) dual gas-switchable thermoresponsive polymers based on a newly synthesized monomer -(2-fluoroethyl amide)--(2-(diethylamino)ethyl) acrylamide, that is, AM(F1EA-DEAE), which bears both O-switchable fluorinated ethyl amide (F1EA) and CO-switchable ,-diethylamino ethyl (DEAE) moieties on its side chain. PolyAM(F1EA-DEAE) samples prepared from reversible addition-fragmentation chain transfer (RAFT) polymerization exhibited good temperature-responsive properties. Their inherent low critical solution temperature (LCST) could be reversibly tuned to different levels by respectively purging O or CO into its aqueous solution. The O-treatment shifted LCST to a higher temperature, while the CO-treatment made the polymer fully water-soluble. The polymer could be readily recovered to its initial state by washing off the trigger gas with an inert gas such as nitrogen. This work provides an effective monomer design approach for the preparation of O and CO dual gas-responsive polymers.