ELECTROKINETIC PHENOMENA IN HOMEOTROPIC LAYERS OF NEMATIC LIQUID CRYSTAL

The work is devoted to the experimental studies of electrokinetic phenomena in oriented samples of a nematic liquid crystal (LC) 5CB, formed inside fiat capillaries with a homeotropic surface orientation. A decay flow of the liquid crystal arising under the action of DC electric field and hydrostatic pressure gradient was experimentally realized and studied by the registration of meniscus' motion in the vertically oriented cylindrical capillary. The dependences of the maximal value of the meniscus' rise and characteristic decay time on the control voltage have been obtained. The analysis of the experimental data was performed in the framework of a simple model, taking into account the dependence of dielectric permittivity on the electrically controlled orientation of LC. The value of zeta potential as well as the effective shear viscosities at different voltages were determined. The obtained data were compared with the results of independent studies.