Symmetry, Epitaxy and Ordering Processes of Supramolecular Assemblies

一些新的合成液晶材料，形成球形或圆柱形纳米结构（超分子组装），类似于某些生物材料将被研究。本研究选择了热致性材料，因为其优点包括易于实验和固有的适用于恶劣环境（温度或真空），电子和多功能复合材料。这些材料在电子应用方面的潜力是显而易见的：具有最快速电荷传输的有机光导体基于柱状组装和液晶排列的原理工作。序序跃迁（例如从柱状到球状）已经确定，并将通过衍射和电子显微镜进行研究。这些反应可以由温度变化或聚合引起。对这些转变的研究将对每个相的结构和稳定性提供重要的理解。通过与PI的几次合作，正在提供同源分子系列，以便确定分子结构对超分子形状和填充的影响。本文将阐明长链和短链molocohs的异同。这些知识将有助于发展有关小型两亲体相行为的理论概念。对这些材料的进一步了解将通过研究它们的有序-无序转变而获得。利用流变学和光学分析，本项目将研究各向同性到柱状的相变和过渡前波动的存在，这将表明无序状态中存在柱状。这种排序转换的控制是至关重要的应用程序中，设备的性能取决于柱的方向。这些材料的表面锚定和流动方向将被探索。这个项目将为研究生提供指导和培训。这个项目也将有利于实验课程的自主部分（在研究生和本科生水平）。自然界中的功能纳米结构（用于信息存储、化学物质和能量的选择性传输以及机械强度和韧性）激发了合成材料的发展。该项目将研究更适合于苛刻环境（如高温或真空）、光电子和多功能复合材料应用的合成无溶剂液晶纳米结构的结构和排序过程。这项工作将与其他实验室的合成工作同时进行，以便确定分子设计的原则。＊＊＊

9806684 Hudson A number of new synthetic liquid crystalline materials that form spherical or cylindrical nanostructures (supramolecular assemblies) that are similar to certain biological materials will be investigated. Thermotropic materials are selected for this study, because of benefits that include experimental ease snd inherent application to harsh environments (temperature or vacuum), electronic and multifuntional ccomposite materials. The potential for electronic application of these materials is clear: the organic photoconductors with the most rapid charge transport operate on the principles of columnar assembly and liquid crystalline alignment. Order-order transitions (e.g. from columnar to spheroidal) have been identified and will be studied by diffraction and electron microscopy. These can be induced either by a temperature changeor by polymerization. Investigation of these transitions will provide significant understanding of thestructure and stability of each phase. Homologous series of molecules are being provided through several collaborations with the PI, so that the influence of molecular architecture on supramolecular shape and packing will be determined. The similarities and differences between long and short chain molocuhs will be elucidated. Such knowledge will be useful input for the development of theoretical concepts concerning the phase behavior of small amphiphiles. Further insight into these materials will be gained through the study of their order-disorder transitions. Using rheological ant optical analysis, this project will investigate the isotropic-to- columnar phase transition and the existence of pretransitional fluctuations that would indicate the presence of columns within the disordered state. The contol of this ordering transition is crucial for applicafions in which the device performance depends on column orientation. Surface anchoring and flow alignment of these materials will be explored. This project w fll provide the instruction and training of a graduate student. This project will also benefit a self directed portion of a laboratory course (at the graduate and undergraduate level). %%% Functional nanostructures in Nature (used for information storage, selective transport of chemicals and energy, and mechanical strength and toughness) inspire synthetic materials development. This project will investigatc the structure and ordering processes of synthetic solvent-free liquid crystalline nanostructures that are more suited to application in demanding environments (such as high temperature or vacuum), photoelectronic and multifunctional composite materials. This work will proceed in parallel with synthetic efforts in other labs so that principles of molecular design can be determined. ***