RUI: Surface Ordering and Anchoring Energy in Nematic Liquid Crystals

9307350摩西，这个项目的目标是使用逝去波椭偏测量仪来测量液晶中界面区域的有序度和厚度，作为各向同性-向列相转变两侧温度的函数。这些结果将允许对当前各向同性-向列相转变附近的液晶表面现象的理论进行批判性评估，并为深入了解液晶表面有序化的微观机制提供依据。此外，还将进行实验，以探索表面锚定能与表面有序或无序的存在之间的联系。锚定能的温度依赖关系将在各向同性向列相转变附近使用高磁场弗里德里克斯兹转变技术和相敏光学检测方法来测量。结合表面有序实验和锚定能测量的结果，应该可以更好地理解液晶中的界面现象。拟议中的调查还将为本科生提供一个熟悉液晶研究和现代相变理论的机会。***

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. ***