Dynamical and Structural Studies of Liquid Crystal Phases

该奖项由科罗拉多博尔德大学材料研究部的生物材料计划颁发，旨在研究液晶相的动力学和结构研究，并由DMR的固态化学计划共同资助。获得这一奖项后，PI将研究只有几个(6-6)碱基对的纳米级双链DNA的液晶(LC)相、形成双乙酰磷脂的管状物理、BURA两亲分子的自由悬浮膜、自由悬浮膜中拓扑缺陷的动力学、单层膜上的多层岛、弯曲核心分子的偏振调制相，以及微米和纳米图案表面上液晶的组织。该项目将探索LC的相结构，导致各向异性LC形成聚集体的分子粘合机制，以及DNA碱基对选择的影响。建议研究的液晶相包括2D向列相到2D近晶A相变；具有三斜对称性的弯芯分子的近晶；近晶薄膜中层对层界面的集体动力学；以及用X射线和光学方法研究这些LC相的结构。液晶是由弱相互作用稳定的相，以不同程度的流体有序化为特征，这种组合使自组织和退火能够在介观和宏观长度尺度上形成易于被场和表面等作用剂操纵的结构。这些研究不仅使液晶在技术上有用，而且直接导致液晶和液晶组织主题在自组装超分子系统的发展中发挥的核心作用。因此，液晶在凝聚态物质科学中继续呈现出引起人们极大兴趣的问题和机会。这项拟议的工作重点是利用光学显微镜、光散射、基于同步加速器的X射线衍射和电子显微镜来研究它们的结构和动力学行为，解决各种软物质系统的物理问题。%这个项目将在液晶取向和弯芯分子非线性光学领域与工业界进行合作。研究生的培训将是该项目的优先事项，国际和平研究所计划制定科罗拉多大学液晶科学和技术方案，重点是开发软物质研究生实验室课程。此外，PI将继续增加CU材料科学计划的新活动，该计划是一个科学教育丰富计划，向科罗拉多州的学生提供动手课程，旨在利用当前对材料的理解教授物理科学概念。对于K-6学生和他们的家长来说，PI计划在过去几年在科罗拉多州博尔德和农村地区演出的液晶奇才表演中充当一名“巫师”。

This award by the Biomaterials program in the Division of Materials Research to University of Colorado Boulder is to study Dynamical and Structural Studies of Liquid Crystal Phases, and is co-funded by the Solid State Chemistry program in DMR. With this award, PI will study liquid crystal (LC) phases of nanoscale duplex DNA with only a few (6 - 6) base pairs, physics of tubule forming diacetylenic phospholipids, freely suspended films of bola amphiphiles, the dynamics of topological defects in freely suspended films, multi-layer islands on monolayer films, polarization-modulated phases of bent-core molecules, and the organization of liquid crystals on micro- and nano-patterned surfaces. The project will probe the LC phase structures, the molecular adhesion mechanism leading to anisotropic LC forming aggregates, and the effects of DNA base pair choices. Liquid crystal phases proposed to study included 2D nematic to 2D smectic A phase transitions; smectic of bent-core molecules with triclinic symmetry; collective dynamics of layer to layer interfaces in smectic films; and X-ray and optical methods to study structural aspects of these LC phases. LCs are phases stabilized by weak interactions and characterized by various degrees of fluid ordering, a combination enabling self-organization and annealing out to mesoscopic and macroscopic length scales into structures that are easily manipulated by agents such as fields and surfaces. These studies not only makes liquid crystals technologically useful, but also leads directly to the central role played by liquid crystals and liquid crystal organizational themes in the development of self-assembled supermolecular systems. Thus liquid crystals continue to present problems and opportunities of extraordinary interest in condensed mater science. The proposed work focuses on the study of their structure and dynamical behavior using optical microscopy, light scattering, synchrotron-based x-ray diffraction, and electron microscopy, addressing issues in the physics of a variety of soft matter systems.%%%With this project, collaborations with industry will be pursued in the area of LC alignment and bent-core molecular nonlinear optics. The training of graduate students will be a priority of this project and the PI plans to develop the University of Colorado Liquid Crystal Science and Technology Program with a focus on the development of a soft-matter graduate laboratory course. In addition, the PI will continue to add new activities with the Materials Science from CU program, a science education enrichment program presenting hands-on classes to Colorado students, and designed to teach physical science concepts using the current understanding of materials. For K-6 students and their parents, the PI plans to serve as a "Wizard" in the Liquid Crystal Wizards Show, which has been performed in Boulder and rural areas of Colorado over the past several years.