Electrooptic Materials Based on Molecular Compasses and Gyroscopes

光子学技术需要能够控制光的偏振、折射和传输的材料。该项目包括基于内部偶极子的旋转动力学寻找具有电光和介电功能的光子材料。为此，制备具有类似于宏观罗盘和陀螺仪的结构和功能的分子的固体被视为优先事项。虽然这些固体已经显示出预期的行为，但在它们的制备和功能的优化方面仍然存在挑战。目前的目标包括制备能够在兆赫和太赫兹制度下响应交变电磁场的结构，并在广泛的聚合物材料中实施，以及光电测试。从事这项研究的研究生接受了彻底的跨学科培训，其中包括复杂的有机合成以及固体材料的结构和动态表征技术。后者包括固体核磁共振、电子能谱、热分析和介电能谱。学生受益于与加州大学洛杉矶分校(UCLA)物理、化学和电气工程系及其他地方的合作者的互动，以及加州大学洛杉矶分校IGERT“材料创造和培训计划”中的大量学术活动。参与该项目的三名西班牙裔博士生有望在未来两到四年内获得博士学位，他们在指导本科生方面有着出色的记录，并将继续这样做。通行证和陀螺仪是海军舰艇和通信卫星上的导航仪器。这些设备的分子版本被认为在未来的技术中提供了新的用途。指南针由一个带有磁化针的刚性盒子组成，它指向地球磁北产生的磁场，而陀螺仪拥有一个快速旋转的轮子，能够报告原本意想不到的方向变化(凭借其角动量)。本项目中研究的指南针和陀螺仪的分子版本具有类似的特性。分子罗盘有一个重新定向的“极针”，能够找到最强的外场，分子陀螺仪有一个旋转的基团，帮助分子抵抗方向的变化。这个项目打算利用数百万这样的分子的集体行为，将它们放在新型显示器和光学计算机中一起工作。大量的分子罗盘或分子陀螺仪被设计成自组装并共同作用。在这样做的过程中，数以百万计的针同时改变方向，将能够弯曲、扭曲和阻挡显示应用和光学计算机所需的光束。用分子陀螺仪制成的材料将具有感应场的能力，这些场的变化速度比最快的液晶显示器快约1亿倍，比我们最快的办公室电脑的处理器快约1000倍。该项目由材料研究部和化学部共同资助。*

Photonics technologies demand materials capable of manipulating the polarization, refraction, and transmission of light. This project comprises a search for photonic materials with electrooptic and dielectric functions based on the rotational dynamics of internal dipoles. Toward that end, the preparation of solids built with molecules having structures and functions that are analogous to those of macroscopic compasses and gyroscopes are viewed as a priority. While these solids have been shown to display the expected behavior, challenges remain in their preparation and on the optimization of their functions. Current goals include the preparation of structures capable of responding to alternating current fields in the mega- and terra-Hertz regimes, and their implementation in a wide range of polymeric materials, and electro-optical testing. Graduate students engaged in this research receive a thoroughly interdisciplinary training that includes complex organic synthesis and techniques for the structural and dynamic characterization of solid materials. The latter include solid state nuclear magnetic resonance, electronic spectroscopy, thermal analysis and dielectric spectroscopy. Students benefit from interactions with collaborators in the Physics, Chemical, and Electric Engineering Departments at the University of California at Los Angeles (UCLA) and elsewhere, and from a large number of academic activities within the UCLA IGERT "Materials Creation and Training Program". Three Hispanic Ph.D. students involved in this project, who are on track to receive their PhD's within the next two to four years, have an excellent record mentoring undergraduate students and will continue to do so. %%%Compasses and gyroscopes are navigational instruments found in Navy ships and communication satellites. Molecular versions of these devices are thought to provide new uses in future technologies. While compasses consist of a rigid box with a magnetized needle that points towards the field created by the Earth's magnetic north, gyroscopes possess a rapidly rotating wheel capable of reporting otherwise unsuspected changes in direction (by virtue of its angular momentum). The molecular versions of compasses and gyroscopes studied in this project have analogous properties. Molecular compasses have a reorienting "polar needle" capable of finding the strongest external field, and molecular gyroscopes have a rotating group that helps the molecule resists changes in direction. This project intends to exploit the collective behavior of millions of such molecules, put to work together in novel displays and optical computers. Large arrays of molecular compasses or molecular gyroscopes have been designed to self-assemble and act together collectively. In doing that, millions and millions of needles changing their direction in unison will be able to bend, twist and block beams of light as required for display applications and optical computers. Materials made with molecular gyroscopes will have the ability of sensing fields that change with speeds that are about 100 million-million times faster than the fastest liquid crystal displays, and about one thousand times faster than the processors of our fastest office computers. This project is co-funded by the Division of Materials Research and the Chemistry Division.***