Nonlinear Optical Spectroscopic Studies of Polymers and Liquid Crystals

聚合物和液晶的非线性光谱研究

• 批准号: 0075402
• 负责人: Yuen Shen
• 金额: $ 28.9万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-15 至 2003-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0075402&HistoricalAwards=false
• 关键词: Nonlinear; Optical; Spectroscopic; Studies; Polymers

This project focuses on three topics: studies of chiral liquid crystalline materials, studies of polymer surfaces and interfaces relevant to liquid crystal alignment, and studies of surface effects on liquid crystal bulk alignment for liquid crystal displays. According to Lord Kelvin, chirality refers to the structural asymmetry of an object whose image in a plane mirror does not coincide with itself. Chiral liquid crystals have become increasingly important to liquid crystal science and technology. More generally, molecular chirality also plays an exceptionally important role in science and technology in science because, for reasons unknown, practically all natural products such as DNA and proteins are chiral. Research will include developing the nonlinear optical spectroscopic technique for unique studies of this special class of liquid crystalline materials. High sensitivity of the technique allows measurements not only on the bulk fluid but also on monolayers, surfaces, and films of chiral liquid crystals. From the spectra near vibrational resonances, chirality and chiral strength in selected atomic groups of chiral molecules will be deduced. They will be correlated to the chiral molecular structure and the macroscopic helical structure of the liquid crystal bulk. The results will yield a better understanding of chirality from the molecular level and chiral liquid crystal properties for potential applications.%%%Liquid crystals have found wide applications in the modern world, with the surface properties often being the determining factors for an application. This research will enhance our knowledge of liquid crystals as extraordinary materials for modern optoelectronic application such as displays and memory and sensor devices. Substrates in liquid crystal displays and other polymer surfaces potentially useful for liquid crystal alignment. The spectroscopic technique also can be used to study liquid crystal monolayers adsorbed at an interface. Information on the orientation and alignment of liquid crystal monolayers is important as they control the bulk alignment of liquid crystal films. A better understanding of the polymer surface structures and their interaction with adsorbed liquid crystal monolayers would be of help to the design of future liquid crystal devices.

本项目集中于三个主题：手性液晶材料的研究，与液晶取向相关的聚合物表面和界面的研究，以及液晶显示器液晶整体取向的表面效应研究。根据开尔文勋爵的说法，手性是指一个物体在平面镜中的图像与其自身不重合的结构不对称。手性液晶在液晶科学和技术中的地位日益重要。更广泛地说，分子手性在科学和科学技术中也扮演着特别重要的角色，因为，由于未知的原因，几乎所有的天然产品，如DNA和蛋白质，都是手性的。研究将包括开发非线性光学光谱技术，对这类特殊的液晶材料进行独特的研究。该技术的高灵敏度不仅可以测量主体流体，还可以测量手性液晶的单分子层、表面和薄膜。从振动共振附近的光谱可以推算出手性分子原子基团的手性和手性强度。它们将与液晶的手性分子结构和宏观螺旋结构相关联。这些结果将有助于从分子水平上更好地理解手性和手性液晶的潜在应用。%的液晶在现代世界中得到了广泛的应用，而表面性质往往是决定应用的因素。这项研究将增进我们对液晶作为现代光电应用的特殊材料的认识，如显示器、存储器和传感器设备。液晶显示器中的基板和其他可能用于液晶对准的聚合物表面。光谱技术也可用于研究吸附在界面上的液晶单分子膜。有关液晶单分子膜取向和取向的信息很重要，因为它们控制着液晶薄膜的整体取向。更好地了解聚合物的表面结构及其与吸附液晶单分子膜的相互作用，将有助于未来液晶器件的设计。