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Self‐Assembled Microspheres Driven by Dipole‐Dipole Interactions: UCST‐Type Transition in Water
Author(s) -
Morimoto Nobuyuki,
Muramatsu Kanna,
Wazawa Tetsuichi,
Inoue Yuichi,
Suzuki Makoto
Publication year - 2014
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201300798
Subject(s) - upper critical solution temperature , copolymer , chain transfer , materials science , peg ratio , polymer chemistry , ethylene glycol , polymerization , chemical engineering , polymer , dispersity , reversible addition−fragmentation chain transfer polymerization , lower critical solution temperature , radical polymerization , composite material , engineering , finance , economics
A double hydrophilic block copolymer, poly(ethylene glycol)‐poly(3‐dimethyl (methacryloyloxyethyl) ammonium propane sulfonate) (PEG‐SB), is synthesized by reversible addition‐fragmentation transfer (RAFT) polymerization using PEG methyl ether (4‐cyano‐4‐pentanoate dodecyl trithiocarbonate) as a chain transfer agent. PEG‐SB forms multi‐layered microspheres with dipole‐dipole interactions of the SB side chains as the driving force. The PEG‐SB polymers show an upper critical solution temperature (UCST) and the UCST is controllable by the polymerization degree. The PEG‐SB microspheres are dissociated above the UCST and then monodispersed microspheres (∼1 μm) are obtained when the solution temperature is decreased below the UCST again. The disassociation/association of the microspheres is also controllable using the concentration of NaCl. These multi‐responsive microspheres could be a powerful tool in the field of nano‐biotechnology.