Amphiphilic block copolymer terminated with pyrene group: from switchable CO2-temperature dual responses to tunable fluorescence
An amphiphilic block copolymer poly(ε-caprolactone)-block-poly(N-isopropylacrylamide-co-N,N-dimethylaminoethyl methacrylate) terminated with a pyrene group (Py-PCL-b-P(NIPAM-co-DMAEMA)) was synthesised by the combination of ring-opening polymerisation (ROP), DCC reaction and reversible addition-fragmentation chain transfer polymerisation (RAFT). The micelles self-assembled from the copolymer and showed switchable CO2-temperature dual responses. The copolymerisation incorporating DMAEMA was used as a CO2-responsive trigger into NIPAM, and the lower critical solution temperature (LCST) value could be switched by the gas. The fluorescence intensities and the controlled drug release properties could be adjusted and achieved by altering the temperature of the micelle solution and bubbling CO2/Ar into the micelle solution.