VERTICAL ALIGNMENT FILM FOR LIQUID CRYSTALS FABRICATED BY MONOMER PHOTOCROSSLINKING.

A new method has been proposed to fabricate liquid crystal vertical alignment films at low temperature. The crosslinking reaction of hexafluorobiphenol A dicinnamate ester took place under unpolarized ultraviolet light. The obtained films could induce vertical alignment for liquid crystals. UV-visible spectra and FTIR spectra revealed that photocrosslinking had occurred and that the degree of crosslinking was rather high. After the aligned film was cured at 120°C for half an hour, the obtained pretilt angles maintained about 90°. [ABSTRACT FROM AUTHOR]