A CO₂- and temperature-switchable "schizophrenic" block copolymer: from vesicles to micelles

CO2-responsiveness is imported into amphiphilic block copolymers, poly[(N,N-diethylaminoethyl methacrylate)-b-(N-isopropylacrylamide)] (PDEAEMA-b-PNIPAM), and a system dual-responsive to CO2 and temperature is constructed. The copolymer self-assembles in aqueous solution, and undergoes phase transition when CO2 and temperature stimuli occur, since the stimuli give rise to the conversion of the hydrophilicity of both blocks. Combining CO2 and temperature as triggers, schizophrenic micelle to vesicle morphological transition of the polymer assemblies is controlled.