title: Anchoring properties of photoaligned azo-dye materials.
abstract: The photoinduced alignment of a liquid crystal (LC) on films of azo dyes was studied for the liquid crystal display applications. In order to improve the alignment stability of the photoaligned dye (SD-1), the azo-dye derivative with polymerizable terminal groups was synthesized (SDA-1). The films of SDA-1 exhibit good photoalignment properties and ultraviolet stability after thermal polymerization. We investigated the anchoring coefficient for polar and azimuthal energy for both azo-dyes SD-1 and SDA-1 using a differential method developed by us. The polar and azimuthal anchoring strengths of azo-dye aligning materials are comparable with those of usual polyimide aligning materials. The electro-optic response of a 90 degrees twisted LC cell remains almost the same after heating up to 200 degrees C, i.e., the anchoring energy remains considerably high.
authors.affiliation: Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. eechigr@ust.hk
authors.forename: Vladimir
authors.initials: V
authors.lastname: Chigrinov
authors.forename: Anatoli
authors.initials: A
authors.lastname: Muravski
authors.forename: Hoi Sing
authors.initials: HS
authors.lastname: Kwok
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takada
authors.forename: Hidenari
authors.initials: H
authors.lastname: Akiyama
authors.forename: Haruyoshi
authors.initials: H
authors.lastname: Takatsu