Photosensitive Triethoxysilane Derivatives for Alignment of Liquid Crystals

Synthesis of a new class of triethoxysilane materials for photoinduced orientation of liquid crystals is reported. A feature of these silanes is the incorporation of a photosensitive chromophore in the chemical structure. This leads to the formation of a complete monolayer with smooth surface morphology. The effect of varying the chemical structure on the kinetics of monolayer formation as well as on the alignment of liquid crystals is discussed. Short hydrocarbon chains at the far end of the silane molecule lead to a uniform planar alignment while longer chains induce a perpendicular alignment of liquid crystal molecules.