3b05 Photoalignment of microphase cylinders in a liquid crystalline azobenzene block copolymer

Abstract

Liquid-crystalline azobenzene block copolymers with poly(butylmethacrylate) block were synthesized by atom transfer radical polymerization. Thin films of the polymers were prepared by spincast method. The films were irradiated with linear polarized visible light (LPL) under liquid crystal phase under LC temperature. The resulting film exhibited the in-plane anisotropy in smectic phase and the microphase separation structure aligned perpendicular to the polarization plane of the LPL. We evaluated orientations of LC phase and microphase separation structure by the polarized absorption spectroscopy and grazing incidence small angle X-ray scattering (GI-SAXS) measurement. Moreover in order to reveal the photoreorientation behavior, we estimate the reorientation domain size from the half-band width of the GI-SAXS data and the polarized microscope measurement at the intermediate state of the photoreorientation process.