Coherent Anti-Stokes Raman Scattering and Fluorescence Confocal Polarizing Microscopy of Three-Dimensional Structures in Liquid crystals

“该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。技术概要：液晶是许多现代技术中的关键材料。 正如诺贝尔奖赢家P.G.德·热内，“...液晶的研究很复杂，因为它涉及到...在三维空间中有一定的视觉，以便可视化复杂的分子结构”。直到最近，为了证实这种视觉感，研究人员和教育工作者依赖于间接信息，如集成的2D图像。 该项目将把最近开发的液晶分子取向三维可视化技术，即所谓的荧光共焦偏振显微镜（FCPM）和相干反斯托克斯拉曼散射（汽车）显微镜，扩展到液晶中静态和动态复杂三维结构的研究。 汽车的一个独特的功能，即无标记的化学敏感性，将被用来建立潜在的双轴取向顺序的化合物中的化学键的取向。 FCPM将被用来探索胶体粒子在液晶介质中的动力学。 指向矢畸变，引入系统中的有限表面锚定在颗粒表面，强烈影响颗粒的动力学，使其从根本上不同于在常规流体中的动力学。 这个问题非常复杂，只能通过该项目提供的3D可视化工具进行访问。 这项研究将在肯特州立大学的液晶研究所进行，该研究所为研究生和本科生培训提供了完善的机制（由NSF本科生研究经验资助），并为工业伙伴关系提供了肥沃的土壤（工业伙伴关系计划，约有30家公司成员）。 所获得的知识将有助于其他项目的潜在的实际利益的社会，即在快速切换显示器和液晶为基础的光学和微流体设备的发展。非技术概述：液晶联合收割机结合晶体和液体的属性。 它们显示出与常规固体晶体相似的光学性质，但同时它们对即使是最弱的外部因素（如小电压脉冲）也非常敏感。它解释了为什么液晶是普遍称为“LCD”的液晶显示器的关键材料。 正如该领域的诺贝尔奖赢家P.G.德·热内，“...液晶的研究很复杂，因为它涉及到...在三维空间中有一定的视觉，以便可视化复杂的分子结构”。 最近，俄亥俄州肯特州立大学液晶研究所的研究人员开发了特殊的显微镜技术，以获得液晶中复杂分子排列的真正三维图像。 研究人员将利用这些仪器来研究液晶中以前无法研究的新的有希望的现象。 一个主题是寻找所谓的双轴晶体管，它有望大大提高液晶显示器的切换速度。 第二个主题是探索在液晶环境中控制小粒子运动的原理。 这里的目标是了解液晶的独特性质是否可以用来推动粒子，从而创造一个胶体微马达。 这项研究将在肯特州立大学的液晶研究所进行，该研究所将研究生和本科生培训与工业伙伴关系计划相结合。 所获得的知识将有助于开发快速开关LCD，微流体和光学器件。 液晶的三维可视化将有助于研究生和本科生掌握现代先进材料科学的本质。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."TECHNICAL SUMMARY:Liquid crystals are the key material in many modern technologies. As stated by the Nobel Prize winner P.G. de Gennes, ''...the study of liquid crystals is complicated because it involves...a certain sense of vision in three-dimensional space in order to visualize complex molecular arrangements''. Until recently, to substantiate this sense of vision..., researchers and educators relied on indirect information, such as integrated 2D images. This project will expand the recently developed techniques of 3D visualization of the molecular orientation in liquid crystals, the so-called Fluorescence Confocal Polarizing Microscopy (FCPM) and Coherent Anti-Stokes Raman Scattering (CARS) microscopy, to the studies of complex three-dimensional structures in liquid crystals, both static and dynamic. A unique feature of CARS, namely, label-free chemical sensitivity, will be used to establish orientation of chemical bonds in compounds with potentially biaxial orientational order. FCPM will be used to explore the dynamics of colloidal particles in the liquid crystal medium. Director distortions, introduced in the system by finite surface anchoring at the particle surface, strongly affect the dynamics of particle, making it radically different from the dynamics in regular fluids. The problem is very complex and can be accessed only with a 3D visualization tool that this project will provide. This research will be conducted at the Liquid Crystal Institute at Kent State University which offers well established mechanisms for graduate and undergraduate training (supported by NSF Research Experience for Undergraduates grant), and a fertile ground for industrial partnership (Industrial Partnership Program with about 30 companies membership). The acquired knowledge would help in other projects with the potential practical benefits to society, namely, in the development of fast switching displays and liquid crystal-based optical and microfluidic devices.NON-TECHNICAL SUMMARY:Liquid crystals combine properties of both crystals and liquids. They show optical properties similar to that of regular solid crystals but at the very same time they are very sensitive to even the weakest external factors, such as a small voltage pulse. It explains why the liquid crystals are a key material in what is universally known as "LCDs", liquid crystal displays. As stated by the Nobel Prize winner in the field, P.G. de Gennes, ''...the study of liquid crystals is complicated because it involves...a certain sense of vision in three-dimensional space in order to visualize complex molecular arrangements''. Recently, researchers at the Liquid Crystal Institute, Kent State University, Ohio, have developed special microscopy techniques to obtain truly three-dimensional images of the complex molecular arrangements in liquid crystals. The researchers will employ these instruments to look into the new promising phenomena in liquid crystals that simply could not be studied before. One theme is a search for the so-called biaxial nematic that promises to dramatically improve the switching speed of LCDs. The second theme is to explore principles that control a motion of a small particle in a liquid crystal environment. The goal here is to learn whether the unique properties of the liquid crystal can be used to propel the particles and thus create a colloidal micromotor. This research will be conducted at the Liquid Crystal Institute at Kent State University that combines graduate and undergraduate training with industrial partnership program. The acquired knowledge would help in the development of fast switching LCDs, microfluidic and optical devices. Three-dimensional visualization of liquid crystals would help both graduate and undergraduate students to grasp the essence of modern science of advanced materials.