X-Ray and Neutron Scattering Studies of Structure and Fluctuation Phenomena in Side Chain Polymer Liquid Crystals

侧链聚合物液晶结构和涨落现象的 X 射线和中子散射研究

• 批准号: 8819680
• 负责人: Satyendra Kumar
• 金额: $ 9.61万
• 依托单位: Kent State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-09-01 至 1992-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8819680&HistoricalAwards=false
• 关键词: Ray; Neutron; Scattering; Studies; Structure

Side chain polymer and elastomer liquid crystals are new classes of materials which uniquely combine two competing phenomena; isotropic fluctuations of polymers and anisotropic orientational and translational order fluctuations of liquid crystals. They exhibit novel nematic liquid crystalline structures and phase transitions, and offer a new perspective on the unsolved nematic- smectic-A problem. A change in the number of spatial dimensions explored by the polymer chain should occur with the establishment of smectic order in these systems accompanied by an interesting cross-over behavior among four relevent length scales. This provides an opportunity to experimentally study the statistical mechanics of a random coil in two dimensions. The synthesis and preliminary studies in this area have been performed mostly outside the United States. They propose here a combination of two powerful techniques, high-resolution x-ray diffraction and small-angle neutron scattering, to study subtle aspects of the structure and critical phenomena in these materials. They proposed research should help bring this interesting area into the main stream of condensed matter research in this country.

侧链聚合物和弹性体液晶是一类新的液晶 独特地结合了联合收割机两种竞争现象的材料; 聚合物的各向同性涨落和各向异性取向 和液晶的平移阶数波动。 他们 显示出新颖的双相液晶结构和相 过渡，并提供了一个新的视角对未解决的问题- smectic-A问题。 空间维度数量的变化 探讨了高分子链的发生与建立 在这些系统中的近晶秩序伴随着一个有趣的 四个相关长度尺度之间的交叉行为。 这 提供了一个实验研究统计的机会， 二维无规卷曲的力学 在这方面的综合和初步研究已 主要在美国境外进行。 他们在这里提出了一个 结合了两种强大的技术，高分辨率X射线 衍射和小角中子散射，研究微妙的 这些结构和关键现象的方面， 材料. 他们建议研究应该有助于 进入凝聚态物质的主流 在这个国家的研究。