Molecular Crystals and Liquid Crystals, Vol.498, 40-48, 2009
Photo-Response Properties of Inverse Opal Infiltrated with Push-Pull Type Azobenzene Functionalized Polymer Liquid Crystals
Azo-containing polymers, poly(DR1Mc), poly(Dc2AzMc) and their copolymers, having push-pull type of azo-group were prepared and their photo-orientation behaviors were investigated. They were infiltrated into silica inverse opal, and reversible Bragg reflection shift was induced by irradiation of light in a range of 500 nm to 600 nm. With linearly polarized light irradiation, Bragg reflection of inverse opal was shifted to longer wavelength region, because azobenzene compounds oriented perpendicular to the axis of incident polarized light and the refractive index contrast was changed. On the other hand, with unpolarized light, Bragg reflection was shifted to shorter wavelength region. This blue shift was due to the molecular orientation preferring parallel to the incident light direction.