title: Photoalignment of an azobenzene-based chromonic liquid crystal dispersed in triacetyl cellulose: single-layer alignment films with an exceptionally high order parameter.
abstract: Single-layer thin alignment films of dye molecules are of growing importance, particularly for state-of-the-art LCD technology. Here we show that a sequential process involving the photoalignment and humidification of a chromonic liquid crystalline azobenzene (brilliant yellow; BY) dispersed in a triacetyl cellulose (TAC) matrix gives a thin alignment film with an exceptionally high order parameter (0.81). Spectroscopic and X-ray diffraction analyses of a BY/TAC composite film in each alignment process revealed that brief humidification triggers restructuring of the BY assembly from 1D nematic-like order to anisotropic 2D columnar order, resulting in the dramatic increase in the order parameter.
authors.affiliation: †Hitachi Research Laboratory, Hitachi, Ltd., 7-1-1 Omika, Hitachi, Ibaraki 319-1292, Japan.|‡Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Matsumori
authors.affiliation: †Hitachi Research Laboratory, Hitachi, Ltd., 7-1-1 Omika, Hitachi, Ibaraki 319-1292, Japan.
authors.forename: Ayami
authors.initials: A
authors.lastname: Takahashi
authors.affiliation: †Hitachi Research Laboratory, Hitachi, Ltd., 7-1-1 Omika, Hitachi, Ibaraki 319-1292, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Tomioka
authors.affiliation: #RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Hikima
authors.affiliation: #RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.affiliation: ‡Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.|#RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kajitani
authors.affiliation: ‡Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Fukushima
keywords: alignment film; azobenzene dye; chromonic liquid crystal; order parameter; photoalignment