Amphidynamic Crystalline Materials Based on Inertial Rotors and Dipolar Arrays

基于惯性转子和偶极阵列的两栖晶体材料

• 批准号: 1101934
• 负责人: Miguel Garcia-Garibay
• 金额: $ 46.5万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1101934&HistoricalAwards=false
• 关键词: Amphidynamic; Crystalline; Materials; Based; Inertial

TECHNICAL SUMMARYThis proposal describes a research plan centered on the design of a novel class of functional materials based on the motion of their molecular units. These materials are said to be amphidynamic in reference to the fact that they have architectural elements that exist at the two extremes of the molecular dynamics spectrum. The long-term vision of this project is to create dense multi-component assemblies with the complexity and addressability that is expected of smart materials and artificial molecular machines. By form and function, the building units selected for this study resemble macroscopic compasses or gyroscopes, with the designation of choice depending on their state of motion and the presence of dipoles that respond to external fields. Their structures consist of a rotary mass, or rotator, that is connected by an axle to a rigid frame that holds the assembly together and plays the role of a stator. Amphidynamic materials based on inertial rotors and dipolar arrays are expected to have addressable mechanic, dipolar, and optical properties for electro-optic and dielectric applications. In analogy to liquid crystals, the new materials will possess birefringence, dichroism, and second-order non-linear optical responses that can be switched on and off with external fields. However, molecular compasses will not require the entire molecule and the bulk domain to reorient so that dipolar lattices with suitable symmetries will have a ferroelectric ground state and response times approaching those given by the moment of inertia of the reorienting units, on the order of 1012 s-1 (THz). With the support of the Solid-State and Materials Chemistry program in the Division of Materials Chemistry and the Macromolecular, Supramolecular, and Nanochemistry program in the Division of Chemistry , the UCLA team will test structures design to display inertial rotation in the solid state, a new family of molecular compasses and gyroscopes with rotary motion that responds to thermal and photochemical stimuli, and will investigate a new class of electrochromic materials based on changes in orientation between linearly conjugated chromophores. Hoping to make an impact on the number of underrepresented minority students who pursue materials research careers, the PI has established a collaboration with Faculty at Trade Technical College, which is located in downtown Los Angeles and has a very large Hispanic and African American population. The PI and his students have outlined plans to disseminate their research to the general public. NON-TECHNICAL SUMMARYThe primary objective of this project, supported by the Solid-State and Materials Chemistry program in the Division of Materials Chemistry and the Macromolecular, Supramolecular, and Nanochemistry program in the Division of Chemistry, is to develop a new class of responsive materials that can be switched on-and-off to manipulate light and electrical signals. This will be accomplished by altering the orientation and motion of the molecules that constitute the material. Notably, molecular motion is not the first thing that comes to mind when thinking about solids. However, recent advances in the PI laboratory have shown that such materials can be built with molecular rotors linked to rigid frameworks by molecular axles and bearings akin to those found in macroscopic machines. The specific structures studied in this project are evocative of a macroscopic compass. They have a bar needle, or "dipole", that rotates about an axle in order to point towards the strongest magnetic or electric field. By collectively changing their orientation in the presence of strong external fields many such molecular compasses within the material can change the intensity, color, and polarization of transmitted light. Using elements designed to change the speed of rotation, the UCLA group aims at changing the speed of signal transmission in order to improve technologies currently used in cell phones and other devices. Research on these so-called "amphidynamic" materials will provide the PI with opportunities to educate and train talented materials chemists and to carry out research activities aimed at increasing the number of students from underprivileged backgrounds that enter the field of materials chemistry. The PI has been very successful attracting women and minority students to his research group by maintaining a highly supportive and creative environment that fosters careers in materials science and in science education. As part of this project, the PI has established several outreach activities in collaboration with Faculty at Trade Technical College, which is located in downtown Los Angeles and has a very large Hispanic and African American population. It is hoped that the most talented students will transfer to UCLA and other research universities to pursue careers in chemistry and materials sciences.

技术概述该提案描述了一项研究计划，该计划以基于分子单元运动的新型功能材料的设计为中心。 这些材料被认为是两性的，因为它们具有存在于分子动力学光谱的两个极端的结构元素。 该项目的长期愿景是创造密集的多组分组件，具有智能材料和人工分子机器所期望的复杂性和可寻址性。 根据形式和功能，本研究选择的建筑单元类似于宏观罗盘或陀螺仪，选择的名称取决于它们的运动状态和对外部场做出响应的偶极子的存在。它们的结构由一个旋转质量或转子组成，该旋转质量或转子通过轴连接到一个刚性框架，该框架将组件保持在一起并起到定子的作用。基于惯性转子和偶极阵列的两亲材料预期具有可寻址的机械、偶极和光学性质，用于电光和介电应用。 类似于液晶，新材料将具有双折射，二向色性和二阶非线性光学响应，可以通过外部场打开和关闭。 然而，分子罗盘将不需要整个分子和本体域重新取向，使得具有合适对称性的偶极晶格将具有铁电基态和响应时间，其接近由重新取向单元的惯性矩给出的响应时间，大约为1012 s-1（THz）。 在材料化学部的固态和材料化学计划以及化学部的大分子，超分子和纳米化学计划的支持下，加州大学洛杉矶分校的团队将测试结构设计，以显示在固态下的惯性旋转，一种新的分子罗盘和陀螺仪家族，具有响应热和光化学刺激的旋转运动，并将研究基于线性共轭发色团之间的取向变化的一类新的电致变色材料。 希望对追求材料研究事业的代表性不足的少数民族学生的数量产生影响，PI与位于洛杉矶市中心的贸易技术学院的教师建立了合作关系，该学院拥有大量的西班牙裔和非洲裔美国人。 PI和他的学生已经制定了向公众传播他们的研究的计划。 非技术总结该项目的主要目标，由材料化学部的固态和材料化学计划以及化学部的大分子，超分子和纳米化学计划支持，是开发一类新的响应材料，可以打开和关闭以操纵光和电信号。 这将通过改变构成材料的分子的取向和运动来实现。 值得注意的是，分子运动并不是思考固体时首先想到的事情。 然而，PI实验室的最新进展表明，这种材料可以通过分子轴和轴承与刚性框架连接，类似于宏观机器中的分子转子。 在这个项目中研究的具体结构是一个宏观指南针唤起。 它们有一个棒针，或“偶极子”，围绕一个轴旋转，以指向最强的磁场或电场。 通过在强外场存在下集体改变它们的取向，材料中的许多这样的分子罗盘可以改变透射光的强度、颜色和偏振。 使用设计用于改变旋转速度的元件，UCLA小组旨在改变信号传输的速度，以改进目前用于手机和其他设备的技术。 对这些所谓的“双动力”材料的研究将为PI提供教育和培训有才华的材料化学家的机会，并开展旨在增加来自贫困背景的学生进入材料化学领域的研究活动。 PI一直非常成功地吸引妇女和少数民族学生到他的研究小组，保持高度支持和创造性的环境，促进材料科学和科学教育的职业生涯。作为这一项目的一部分，PI与位于洛杉矶市中心的贸易技术学院的教师合作开展了几项外联活动，该学院有大量的西班牙裔和非洲裔美国人。 我们希望最有才华的学生将转移到加州大学洛杉矶分校和其他研究型大学，从事化学和材料科学的职业。