Photochemical manipulation of discotic liquid crystal alignment by a poly(vinyl cinnamate) thin film

This letter describes the surface-assisted orientational photocontrol of discotic liquid crystals (DLCs) using thin films of a conventional photoresist, poly(vinyl cinnamate). Oblique illumination of a thin film of the polymer with nonpolarized UV light gave rise to inclined orientation of cinnamoyl moieties toward the light propagation through their direction-selective photochemical reactions. The DLCs were aligned on the photoirradiated film in a tilted hybrid manner, whereas the orientational direction of DLC molecules corresponds to the light propagation as a result of three-dimensional orientation of the cinnamoyl residues. (C) 2000 American Institute of Physics. [S0003-6951(00)02443-8].