title: Alignment of liquid crystals on a photosensitive substrate studied by surface optical second-harmonic generation
abstract: The adsorption kinetics and orientational ordering of 4(')-n-octyl-4-cyanobiphenyl (8CB) liquid crystal films evaporated onto photosensitive poly(vinyl-cinnamate) (PVCN) substrates were investigated by surface optical second-harmonic generation. The adsorption rate of the first monolayer decreases with increasing degree of photochemical modification of the polymer. The in-plane orientational anisotropy of the 8CB films grown on unidirectionally photopolymerized PVCN substrates is considerably lower than the intrinsic surface orientational anisotropy of these substrates, which can explain the generally found weak surface anchoring of liquid crystals on PVCN alignment layers.
authors.affiliation: Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI 1000, Ljubljana, SloveniaJ. Stefan' Institute, Jamova 39, SI 1001 Ljubljana, Slovenia.
authors.lastname: Drevensek Olenik I
authors.initials: MW
authors.lastname: Kim
authors.initials: A
authors.lastname: Rastegar
authors.initials: T
authors.lastname: Rasing