Journal of Applied Polymer Science, Vol.89, No.4, 943-951, 2003
Preparation of liquid crystalline networks doped with azobenzene molecules and their photochemical grating formation behavior
Liquid crystalline (LC) networks with macroscopically uniaxial molecular orientation were prepared by photopolymerization of mixtures of LC mono- and diacrylates and a donor-acceptor azobenzene compound in a homogeneous glass cell at the nematic phase, and their photoresponsive properties were investigated. The transparency of the LC networks decreased with a decrease in the crosslinking density with LC diacrylate. The LC networks crosslinked with a few mol percent of LC diacrylate showed an enantiotropic phase transition from an anisotropic phase to an isotropic phase as well as high transparency. Formation and removal of the grating were investigated by irradiating two writing beams with an argon ion laser. Grating less than 1.0 mum could be achieved, and the response time of formation and removal of the grating were in a range of a few tens of microseconds. (C) 2003 Wiley Periodicals, Inc.