Dilution of nematic surface potentials: Relaxation dynamics

Abstract

Surface potentials can be regarded as diluted in space. By use of such a dilution model and Ericksen-Leslie theory we study the free relaxation of a nematic liquid crystal on an anchoring surface, after removal of an applied disorienting field. Depending on the initial distortions, we find either a relatively slow relaxation controlled by the bulk, or a fast relaxation characteristic of the anchoring surface. Comparing the dynamics described by the dilution model to one where the surface potential is localized, we estimate the surface viscosity in terms of the extension length of the surface torques.