Modeling of Photoinduced Optical Anisotropy and Anchoring Energy of Polyimide Exposed to Linearly Polarized Deep UV Light

However, no theoretical analysis of the photodecomposition alignment mechanism has been carried out. The photochemical mechanism is different for photopolymerization and photodecomposition, but the origin of the photoalignment of the LC is a UV dichroic absorption of the alignment material molecules. Therefore, we applied the model previously proposed for the photopolymerization of PVCi to the mechanism for photodecomposition alignment of LC by linearly polarized deep UV (LPDUV) light exposed polyimide. In this paper, we will describe the theoretical model for polyimide exposed to LPDUV light, using the same approach as in previous studies. 7‐9) We will also examine the validity of the model by fitting it to the experimental data. To obtain the experimental data, we measured the retardation of LPDUV-exposed polyimide, the order parameter of liquid crystal aligned by the LPDUV exposed polyimide, and the polar and azimuthal anchoring energy of the interface between nematic liquid crystals and LPDUV-exposed polyimide.