화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.375, 155-164, 2002
Temperature dependence of azimuthal anchoring strength measured by dynamic light scattering
Temperature dependence of the azimuthal anchoring energy coefficient of the nematic 5CB on rubbed Nylon is studied using the dynamic light scattering experiment. The method is based on observations of director fluctuations in a planarly aligned nematic liquid crystal cell. The fluctuation relaxation rate depends not only on cell thickness, but also on the surface anchoring strength. Thus, by measuring relaxation times in a wedge cell, the anchoring energy coefficient can be obtained without any external torques acting on the liquid crystal. We measured the anchoring strength in a broad temperature range and found that the anchoring decreases steadily when approaching the nematic to isotropic transition. A comparison with existing theoretical models is made and an excellent agreement with the mean-field model is observed even in the vicinity of the N-I transition.