Premium
Photo‐alignment material with azobenzene‐functionalized polymer linked in film
Author(s) -
Watanabe Hirohmi,
Miyagawa Nobukazu,
Takahara Shigeru,
Yamaoka Tsuguo
Publication year - 2002
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.225
Subject(s) - azobenzene , materials science , chromophore , polymer , ether , vinyl ether , polymer chemistry , chemical engineering , liquid crystal , photochemistry , optoelectronics , organic chemistry , composite material , monomer , chemistry , engineering
Application of a new azo‐polymer as a photo‐alignment material for liquid crystals (LCs) was demonstrated. 4‐(Vinyloxyethyloxy)azobenzene (VAZO), which has thermally reactive vinyl ether groups, reacted with the OH groups of poly(4‐hydroxystyrene) (PHS) during the baking process. The azo‐attached polymer (PHS‐VAZO) film showed anisotropic spectra after exposure to 365‐nm linear polarized light (LPL) unlike the VAZO‐doped poly(methylmethacrylate) (PMMA) film. The anisotropy of the film was small at high concentration of the azo‐chromophore because of thermal randomization of the polarized state. In the evaluation of photo‐alignment of the LC, the LC hybrid cell using the PHS‐VAZO film achieved high LC alignment. The azo‐attached polymer using the thermal reaction of vinyl ethers is useful for a photo‐alignment material. Copyright © 2002 John Wiley & Sons, Ltd.