Premium
Phototropic Multiresponsive Active Nanogels
Author(s) -
Otsuka Issei,
Zhang Xuewei,
Winnik Françoise M.
Publication year - 2019
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.201900479
Subject(s) - spiropyran , photochromism , merocyanine , nanogel , raft , methacrylic acid , chain transfer , photochemistry , polymer chemistry , irradiation , aqueous solution , polymerization , polystyrene , photoisomerization , chemistry , materials science , radical polymerization , isomerization , organic chemistry , drug delivery , polymer , catalysis , physics , nuclear physics
Aqueous dispersions of nanogels that respond to switches in environmental pH and/or temperature by changes in their hydrodynamic radius ( R h ) and/or ζ‐potential are prepared by reversible addition‐fragmentation chain‐transfer (RAFT) polymerization‐induced thermal (70 °C) self‐assembly (PITSA) of N ‐isopropylacrylamide (NIPAM) in the presence of a poly(methacrylic acid) (PMAA)‐substituted macromolecular chain transfer agent and a cross‐linker. Photochromic spiropyran (SP) moieties are coupled to the carboxylic acid groups of the nanogels. Upon UV irradiation, the neutral SP isomerizes to the zwitterionic merocyanine (ME) form. Upon UV light irradiation, microgels formed by assembly of SP nanogels undergo a collective motion toward the UV‐light source.