Oxygen and carbon dioxide dual gas-responsive homopolymers and diblock copolymers synthesized via RAFT polymerization

The monomer, 2,2,2-trifluoroethyl 3-( N -(2-(diethylamino)ethyl)acrylamido)propanoate (TF-DEAE-AM), which contains both O 2 and CO 2 -responsive functionalities, was first synthesized from commercially available N , N -diethylethylenediamine, 2,2,2-trifluoroethyl acrylate, and acryloyl chloride. Subsequently, a series of dual-gas responsive polymers, poly(2,2,2-trifluoroethyl 3-( N -(2-(diethylamino)ethyl)acrylamido)propanoate) (poly(TF-DEAE-AM)) and poly(ethylene glycol)- b -poly(2,2,2-trifluoroethyl 3-( N -(2-(diethylamino)ethyl)acrylamido)propanoate) (PEG- b -poly(TF-DEAE-AM)), were synthesized by employing reversible addition–fragmentation chain transfer (RAFT) polymerization. Due to the protonation between CO 2 and DEAE groups, and the specific van der Waals interactions between O 2 and C–F bonds, micelles consisting of poly(TF-DEAE-AM) or PEG- b -poly(TF-DEAE-AM) display distinct CO 2 and O 2 responsiveness in aqueous media. Pyrene, which is a model hydrophobic drug, is able to be effectively encapsulated in the micelles based on PEG- b -poly(TF-DEAE-AM). It is found that the release of pyrene sharply increases after bubbling CO 2 or O 2 compared to N 2 , and the release rate of the solution bubbling with CO 2 is the fastest. Since both CO 2 and O 2 are key gases for the human body, the CO 2 - and O 2 -induced release property of poly(TF-DEAE-AM) may open opportunities for the preparation of functional materials with special CO 2 and O 2 responsiveness for potential applications in biomedicine.