Photoluminescent color tuning in fluorene derivative/copolymer composite films based on H-bonds.
Reversible addition-fragmentation chain transfer (RAFT) polymerization is used to synthesize diblock and random copolymers of poly[(2-trifluoroethyl methacrylate)-co-(methacrylic acid)]. Copolymer films doped with fluorene derivatives comprised of pyridine groups exhibit reversible photoluminescent (PL) color tuning by adjusting the location of fluorene derivatives in H-bonds or non-H-bonds environments. The composite films exhibit green and blue photoluminescence with and without effective H-bonding between the pyridine ring in the fluorene derivative and the carboxylic acid side group, respectively. At elevated temperatures, the H-bonded structure dissociates and the fluorene derivative migrates to the hydrophobic block in the diblock polymer, and they do not form H-bonds upon cooling. However, re-formation of H-bonds also occurs upon cooling random copolymers. Moreover, adjusting the annealing temperature and the solvent annealing reversibly tunes the PL color in the diblock copolymer composite films.
Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, Hyogo, Japan. kawatuki@eng.u-hyogo.ac.jp
Nobuhiro
N
Kawatsuki
Hisako
H
Miki
Mizuho
M
Kondo
Mitsunobu
M
Nakamura