Elasticity, Deformation, Rearrangement & Assembly in Complex Fluids

非技术摘要拟议的实验研究将在两个主要科学和技术领域产生影响：如何制造更坚韧的材料和如何将液晶显示技术的想法应用于新的水基液晶系统。总的来说，该计划开发了新的能力来制定和操作微米和纳米粒子以及溶液中的大分子。因此，这项研究加强了支持美国传感/驱动、微流体、药物输送、光子学、印刷、涂料、化妆品和农业等行业应用努力的科技企业。该项目将培养新一代软材料、配方、先进光学显微镜、光电、微流体、流变学和计算领域的科学家和工程师。完成后，博士生和博士后进入劳动力大军，加强美国的技术和经济基础设施；此外，每年夏天，我们的实验室通常会刺激不同的本科生和高中生群体学习STEM教育/职业选择。技术摘要拟议的项目旨在提高关于复杂流体和软材料的知识，但许多发现也将引起硬凝聚态物质、化学工程和材料科学界的兴趣。拟议的实验是统一的，因为他们的重点是微观力学，广义的。其中一套将测量胶体玻璃和晶体的结构和动力学性质，目的是确定这些材料中“软”的区域，并表现出更大的变形或重新排列的倾向。第二组将研究溶致变色液晶。这些液晶的不同寻常之处在于它们很容易扭曲，导致非手性介晶形成手性结构，它们表现出从分子到棒状介晶再到LC相的两个层次的组装层次，并且它们是水溶性的。这些性质的后果将通过扩散实验来探索，这些扩散实验跟踪局部LC导向场覆盖的粒子的运动，通过研究“极端”受限几何形状中弹性能和分子组装层次之间的竞争，以及在新的多相液滴的“干燥”中。总的来说，这些实验使用先进的光学显微镜、光散射和流变学来观察样品，它们需要通过受控悬浮化学和物理、微流体等来配制新型软材料。例如，具有不同形状、相互作用和原位操纵潜力的胶体颗粒正在/将被开发。

Non-technical AbstractThe proposed experimental research will have impact in two major science and technology arenas: how to make a tougher material and how to adapt ideas of liquid crystal display technology to new water-based liquid crystal systems. Broadly, the program develops new ability to formulate and manipulate micro- and nano-particles and macromolecules in solution. Thus the research enhances the science and technology enterprise that underpins applications efforts for US industries involved with sensing/actuation, microfluidics, drug delivery, photonics, printing, coatings, cosmetics and agriculture. The program will train a new generation of scientists and engineers in soft materials, formulation, advanced optical microscopy, electro-optics, microfluidics, rheology & computation. After finishing, PhD students & post-docs enter the work force and strengthen US technological and economic infrastructure; furthermore, a diverse group of undergraduate and high school participants are typically stimulated every summer in our laboratory to pursue STEM education/career choices.Technical AbstractThe proposed program aims to advance knowledge about complex fluids and soft materials, but many findings will also interest the hard condensed matter, chemical engineering and materials science communities. The proposed experiments are unified by their focus on micro-mechanics, broadly defined. One set will measure structural and dynamical properties of colloidal glasses and crystals with goals to identify regions within these materials that are "soft" and exhibit increased propensity to deform or rearrange. A second set will investigate lyotropic chromonic liquid crystals. These liquid crystals are unusual in that they twist very easily which leads to formation of chiral structures from achiral mesogens, they exhibit two levels of assembly hierarchy from molecules to rod-mesogens to LC phases, and they are water soluble. The consequences of these properties will be probed by diffusion experiments which track motions of particles dressed by local LC director fields, by study of the competition between elastic energy and molecular assembly hierarchy in "extreme" confined geometries, and in novel "drying" of multi-phase droplets. Collectively, the experiments use advanced optical microscopies, light scattering and rheometry for sample observation, and they require formulation of novel soft materials via controlled suspension chemistry and physics, microfluidics, etc. For example, colloidal particles with different shapes, interactions and potential for in-situ manipulation are/will-be developed.