Alignment of nematic liquid crystals on an electrically poled photopolymer film

Abstract

We have observed liquid crystal alignment on an electrically poled polyvinylcinnamate film in which a polar symmetry was introduced by an in-plane electric field and stabilized by unpolarized ultraviolet light. The azimuthal anchoring energy and pretilt angle was measured in a twisted nematic or planar cell and is explained via the molecular structure of the unreacted cinnamates and of the photoproducts beta -truxinates. Cinnamates mainly contribute via a strong flow alignment, while beta -truxinate produces the anisotropic properties of the film such as its polar anisotropy, azimuthal anchoring, and pretilt angle. (C) 2001 American Institute of Physics.