AZIMUTHAL SURFACE GLIDING OF A NEMATIC LIQUID-CRYSTAL

In-plane surface gliding of a thermotropic nematic liquid crystal is i nvestigated at substrates with weak azimuthal anchoring energy under d ifferent external electric fields parallel to the substrates. The anch oring is a result of photoinduced anisotropy in a poly-(vinyl)-alcohol alignment layer with embedded azodye molecules. The experimentally me asured time constant, which describes the gliding, is inversely propor tional to the electric field strength. The surface viscosity value of the liquid crystal director at the substrates extracted from the prese nted model is estimated as gamma(s) greater than or equal to 0.33 Js/m (2). (C) 1997 American Institute of Physics.