Uniform Alignment of Liquid Crystals Induced by Perfluoropolyether Film Exposed to Linearly Polarized Ultraviolet Light

Abstract

We have succeeded in inducing uniform alignment of liquid crystal (LC) molecules by using end-functionalized-perfluoropolyether (PFPE) (Fluorocur® made by Liquidia Technologies) films exposed to linearly polarized ultraviolet light (LPUVL). The average orientation direction of LC molecules was parallel to the polarization direction of LPUVL, which is opposite to most cases of other photo-alignment treatments. In the photo-alignment treatment, use of deep UV light and the existence of oxygen in the atmosphere was found to be important for inducing uniform LC alignment.

Keywords:

• Liquid crystal
• perfluoropolyether
• photo-induced alignment

A part of this work was supported by the HRC project (MEXT.HAITEKU 2006–2010) of the Ministry of Education, Culture, Sports, Science and Technology of Japan. We would like to thank M. Fukuda and M. Morita of Teijin DuPont Films Japan Ltd. for supplying the PET film used in this work.