抄録
By using polarized infrared absorption spectroscopy, we have determined the average inclination angle of polyimide backbone structure in photo-aligned films. Polyimide used in this study contains azobenzene in the backbone structure. Photo-alignment treatment was performed for the corresponding polyamic acid film, using a light source of wavelength 340 〜 500 nm. The polyamic acid film (〜16 nm thick) was first irradiated at normal incidence with linearly polarized light (LP-light) of 156 J/cm^2, and then oblique angle irradiation of unpolarized light (UP-light) was performed in the plane of incidence perpendicular to the polarization direction of LP-light. We found that the average inclination angle of the polyimide backbone structure, measured from the surface plane, increases with the UP-light exposure.
