Studies of Cholesteryl Oleyl Carbonate in its Isotropic and Homeotropic States Using Optical Rotation, Kerr-Effect and Light-Scattering Techniques

Abstract

Abstract The temperature dependence of optical rotation, static and dynamic Kerr-effect, and polarized and depolarized dynamic light-scattering for cholesteryl oleyl carbonate has been studied in a range including the isotropic liquid, homeotropic, and supercooled homeotropic states. Above the isotropic-cholesteric liquid crystal transition, marked pre-transitional effects are observed and are interpreted in terms of the build-up of angular correlations between molecules. On supercooling through this transition the observed magnitudes and correlation times are continuous well into the supercooled region, but show a smaller variation with temperature than that observed in the pre-transition range due, apparently, to a tendency for the angular correlation factors to saturate at the lowest temperatures. These data are discussed in relation to mean-field theory for mesogens and to the nature of the phase transformations between isotropic liquid, homeotropic liquid, and cholesteric focal-conic liquid crystal s...