Shape-switching self-assembly of new diblock copolymers with UCST-type and LCST-type segments in waterElectronic supplementary information (ESI) available: Turbidity curves of an aqueous solution of MOVE200-b-([EtIm][BF4])200 containing NaBF4. See DOI: 10.1039/c5py01976a

• Main Authors: Yoshimitsu, H, Korchagina, E, Kanazawa, A, Kanaoka, S, Winnik, F. M, Aoshima, S
• Format: Journal Article
• Published: 08.03.2016
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/c5py01976a

A dual thermosensitive behavior, i.e. , self-assembly at both high and low temperatures, was achieved in water using vinyl ether block copolymers with imidazolium salt side-chains (exhibiting a UCST behavior) and oxyethylene side-chains (exhibiting an LCST behavior). The block copolymers were precisely prepared via living cationic polymerization in the presence of a weak Lewis base. They formed micelles at lower temperatures and vesicles at higher temperatures in water, as confirmed via UV-Vis spectroscopy, dynamic light scattering (DLS), static light scattering (SLS), variable temperature 1 H NMR, and fluorescence measurements using pyrene as a polarity-sensitive probe. Furthermore, concentrated aqueous solutions of the block copolymers underwent sol-gel transitions by either raising or lowering the temperature. Novel dual thermosensitive diblock copolymers with an imidazolium salt and oxyethylene side-chains which self-assemble into micelles and vesicles in water depending on the temperature are precisely synthesized.