9307350 Moses The goal of this project is to use evanescent-wave ellipsometry to measure the degree of order and thickness of the interfacial region in liquid crystals as functions of temperature of both sides of the isotropic-nematic transition. The results will allow a critical evaluation of current theories of liquid crystal surface phenomena near the isotropic-nematic transition, as well as providing insight into the microscopic mechanism of surface ordering in liquid crystals. Also, experiments will be undertaken to explore the connection between the surface anchoring energy and the presence of surface ordering or disordering. The temperature dependence of the anchoring energy will be measured in the vicinity of the isotropic- nematic transition using a high-magnetic-field Freedericksz transition technique in conjunction with a phase-sensitive optical detection method. Combining results from surface ordering experiments and anchoring energy measurements should lead to a better understanding of interfacial phenomena in liquid crystals. The proposed investigation also will provide undergraduate students an opportunity to become familiar with research on liquid crystals and modern theories of phase transitions. ***
