Transport and Equilibrium Properties of Liquid Crystals

格伦·埃文斯教授得到了理论和计算化学计划的资助，该计划研究液晶流体的简单模型系统的结构和动力学。为了简单起见，液晶形成分子被设想为被球形(方井)势包围的坚硬的非球形物体。提出的平衡现象分析涉及到向列相和近晶相、流体混合物和手性向列相的相图的推导。结合密度泛函理论、Onsager理论和标度粒子理论分析了这些相在高液体密度下的成因。需要研究的动力学性质包括：单组分向列相流体的自扩散系数、介电常数和核磁共振谱密度。液晶是在大约一百年前发现的。它们是具有液体的流动特性和固体的光学特性的材料。从那时起，LCD的这些光学和流体特性就被利用到了显示技术中。支撑液晶显示系统发展的分子物理学是不平凡的。液晶显示器通常由具有不同寻常的光学和粘弹性的手性向列相的混合物制成。这些相的技术应用的丰富性反过来又与它们的热力学和传输性质的多样性直接相关，这是埃文斯教授研究的主题。

Professor Glenn Evans is supported by a grant from the Theoretical and Computational Chemistry Program to study structure and dynamics of simple model systems for liquid crystalline fluids. For simplicity, the liquid crystalline forming molecules are envisioned as hard nonspherical bodies encircled with a spherical (square well) potential. The proposed analysis of equilibrium phenomena are concerned with the derivation of phase diagrams for nematic and smectic phases, fluid mixtures and chiral nematics. Elements of density functional theory, Onsager theory and scaled particle theory are combined to analyze the origin of these phases at high liquid densities. The dynamical properties to be addressed include: the self diffusion coefficient, the dielectric permittivity and the NMR spectral density for a single component nematic fluid. %%% Liquid crystals were discovered roughly one hundred years ago. They are materials with flow properties of a liquid and the optical properties of a solid. Since that time, these optical and fluid properties of LCs have been harnessed into display technology. The molecular physics underpinning the development of LCs is nontrivial. Liquid crystal displays are typically made from mixtures of chiral nematic phases with unusual optical and viscoelastic properties. The richness of the technological applications of these phases is in turn directly linked to the diversity of their thermodynamic and transport properties which are the subject of Professor Evans studies.