Dynamical and Structural Studies of Liquid Crystal Phases

该奖项由科罗拉多大学博尔德分校材料研究部生物材料项目颁发，旨在研究液晶相的动力学和结构研究，并由DMR固态化学项目共同资助。有了这个奖项，PI将研究只有几个（6 - 6）碱基对的纳米级双链DNA的液晶相，小管形成二乙基磷脂的物理学，波拉两亲体的自由悬浮膜，自由悬浮膜中拓扑缺陷的动力学，单层膜上的多层岛，弯曲核分子的极化调制相，以及微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LC形成聚集的各向异性分子粘附机制，以及DNA碱基对选择的影响。拟研究的液晶相包括二维向列到二维近晶A相变；具有三斜对称的弯核分子的近晶smic薄膜层间界面的集体动力学以及x射线和光学方法来研究这些LC相的结构方面。lc是由弱相互作用稳定的相，其特征是不同程度的流体有序，这种组合可以使自组织和退火到介观和宏观长度尺度，从而形成易于被场和表面等介质操纵的结构。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所起的核心作用。因此，液晶继续在凝聚态科学中呈现出非常有趣的问题和机会。本文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学问题。在这个项目中，将在LC对准和弯核分子非线性光学领域与工业界合作。研究生的培养将是这个项目的重点，项目负责人计划发展科罗拉多大学液晶科学与技术项目，重点发展软物质研究生实验课程。此外，PI将继续增加CU材料科学项目的新活动，这是一个科学教育丰富项目，为科罗拉多州的学生提供实践课程，旨在利用当前对材料的理解教授物理科学概念。对于K-6年级的学生和他们的家长，PI计划在过去几年在博尔德和科罗拉多州农村地区举行的液晶巫师表演中担任“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.