首页> 外文学位 >Synthesis and characterization of novel glassy liquid crystals.
【24h】

Synthesis and characterization of novel glassy liquid crystals.

机译:新型玻璃态液晶的合成与表征。

获取原文
获取原文并翻译 | 示例

摘要

As an emerging class of photonic and electronic materials, glassy liquid crystals are capable of preserving in the solid state molecular order characteristic of liquid crystals. Because of superior chemical purity and favorable rheological properties, glassy liquid crystals can be readily processed into large-area monodomain films. This thesis aimed at deterministic synthesis of glassy chiral nematics, photochromic glassy nematics, and glassy discotics. The most significant contributions are recapitulated as follows: (1) Through deterministic synthesis of multifunctional materials via enzymatic and chemical approaches, enantiomeric glassy chiral nematics were prepared efficiently and shown to possess a glass transition temperature over 60°C and a cholesteric fluid temperature range wider than 100°C. Device concepts were also demonstrated for high-performance circular polarizers, notch filters and reflectors in the ultraviolet, across the visible, and to the infrared region. (2) The first photochromic glassy nematic liquid crystal was successfully designed, synthesized and characterized to possess a glass transition temperature over 100°C and a clearing point over 200°C. A large-area solid film was prepared through melt processing to demonstrate high-speed switching of anisotropic refractive indices and optical birefringence as a novel approach to rewritable optical memory and photonic switching in solid films. (3) Glassy discotic liquid crystals were synthesized and characterized by x-ray diffraction, polarizing optical microscopy, differential scanning calorimetry, and dynamic mechanical analysis to reveal sub-freezing glass transition temperatures. However, the absence of recrystallization at room temperature over a period of over four years was a manifestation of morphological stability of the discotics.
机译:作为一种新兴的光子和电子材料,玻璃态液晶能够保持液晶的固态分子有序特性。由于优异的化学纯度和良好的流变性能,玻璃状液晶很容易加工成大面积的单畴膜。本论文旨在确定性地合成玻璃状手性向列相,光致变色玻璃状向列相和玻璃态圆盘体。总结最重要的贡献如下:(1)通过酶和化学方法确定性合成多功能材料,对映体玻璃状手性向列化合物得到了有效制备,并显示出其玻璃化转变温度超过60°C,胆甾醇液温度范围更广高于100°C。还演示了在紫外光,可见光和红外光区域的高性能圆偏振器,陷波滤光片和反射器的设备概念。 (2)成功设计,合成并表征了首个光致变色玻璃状向列液晶,其玻璃化转变温度超过100°C,透明点超过200°C。通过熔融加工制备了大面积的固体膜,以证明各向异性折射率和光学双折射的高速转换,这是固体膜中可重写光学存储和光子转换的一种新方法。 (3)合成了玻璃质盘状液晶,并通过X射线衍射,偏振光学显微镜,差示扫描量热法和动态力学分析对其进行了表征,以揭示亚冻结的玻璃化转变温度。但是,在四年多的时间内没有在室温下重结晶是碟形碟片形态稳定性的体现。

著录项

  • 作者

    Chen, Huang-Ming Philip.;

  • 作者单位

    The University of Rochester.;

  • 授予单位 The University of Rochester.;
  • 学科 Engineering Materials Science.; Chemistry Organic.; Physics Optics.
  • 学位 Ph.D.
  • 年度 2003
  • 页码 193 p.
  • 总页数 193
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 工程材料学;有机化学;光学;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号