23 September 2016 Pretilt angle of liquid crystals generated by polyimide photoalignment layers treated with vapor of primary and tertiary alkylamines
Author Affiliations +
Abstract
We have investigated the pretilt angle of liquid crystals generated by photoalignment layers of polyimide containing azobenzene in the backbone structure (Azo-PI). Three different photoalignment layers were prepared by performing or not performing alkylamine vapor treatment on the precursor (polyamic acid: Azo-PAA) films. Octadecyamine (ODA) and N,N-dimethylhexadecylamine (DMHDA) were used as a primary and a tertiary alkylamines, respectively. When unpolarized light irradiation of 114 J/cm2 was performed at an angle of incidence of 45°, the pretilt angles generated by the conventional (without alkylamine vapor treatment), ODA-treated, and DMHDA-treated photoalignment layers were 1.4°, 19°, and 4.3°, respectively. From these results, we found that the pretilt angle generated by Azo-PI photoalignment layers increased by performing alkylamine vapor treatment but the degree of increase strongly depended on the class of alkylamine. To understand the increase in the pretilt angle by the alkylamine vapor treatments, the alignment behaviour of the Azo-PAA (PI) backbone structure in each preparation step was examined and discussed.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kenji Sakamoto, Kenji Sakamoto, Kiyoaki Usami, Kiyoaki Usami, Shogo Kiyohara, Shogo Kiyohara, Kazushi Miki, Kazushi Miki, } "Pretilt angle of liquid crystals generated by polyimide photoalignment layers treated with vapor of primary and tertiary alkylamines", Proc. SPIE 9940, Liquid Crystals XX, 994008 (23 September 2016); doi: 10.1117/12.2235677; https://doi.org/10.1117/12.2235677
PROCEEDINGS
9 PAGES


SHARE
Back to Top