CAREER: Nanostructural Control of Optical Properties in Polymers with Electroactive Subunits

职业：具有电活性亚基的聚合物光学性质的纳米结构控制

• 批准号: 0449688
• 负责人: Padma Gopalan
• 金额: $ 44.5万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0449688&HistoricalAwards=false
• 关键词: CAREER; Nanostructural; Control; Optical; Properties

This proposal describes a five-year plan of integrated research, education, and outreach onnanostructured polymer composites with electroactive molecular subunits. The PI brings her expertise in block copolymer synthesis/ morphological characterization and in the design of electro-optic materials to this research. These two areas of expertise are combined in the proposed research, allowing the PI to develop an integrated research program which will further her career in the field of nanostructured materials.Nanostructured materials such as self-assembled block copolymers or dendrimers constitute a unique class of materials with wide ranging applications in drug delivery systems, nanoelectronics, electro-optics, and photonic band-gap materials. The basic principle in all these applications is confining a biologically active or electroactive component within specific size and shape.For example, the area of electro-optic (EO) polymers has experienced unprecedented growth in the last five years with the development of next generation higher EO coefficient chromophores and prototype devices such as broad-band modulators and photonic phase shifters. Factors such as chromophore, polymer host and cladding material design have been independently optimized to achieve chromophores with EO coefficient 100pm/V and polymer hosts with less than 0.1db/cm losses. However, a fundamental understanding of the interface between the chromophore and polymer host remains elusive. Exploiting the chromophore/polymer interface therefore represents an additional, largely unexplored degree of freedom in controlling the nanomorphology and ultimately the macroscopic EO activity.The intellectual impact of the proposed research program is controlling the size and shape of domains with active molecular subunits by chemical and physical means. These strategies will be demonstrated for the specific case of rational design of nanostructured EO materials and can be easily adapted for other materials containing conjugated units. The primary objectives in the proposed work involve: a) Design chemical means of tailoring the nanodomains by altering the normally incompatible chromophore and polymer host via designed interfaces; b) Design strategies to exploit phase separation of block copolymers to generate polarized EO domains; c) Morphological characterization and optical measurements to develop a model for the structure-property relationship of the functional nanostructures. The first twoobjectives achieve the purpose of controlling the size and shape of active nano-domains by chemical means and directly feed into the third overall objective of correlating the morphology to the observed activity. Experimental investigation of the resulting morphology will be carried out by transmission electron microscopy (TEM) and in situ X-ray diffraction studies under applied DC field.The research career plan is closely integrated with an equally motivated education and outreachprogram incorporating both conventional courses and extensive mentoring. The PI will develop the first polymer course Polymeric Materials in the Materials Science and Engineering department at University of Wisconsin, Madison with a major emphasis on nanostructured electronic polymers. This course will fill the needs of a traditionally hard-materials department by educating materials engineers on the chemical design aspects of a polymeric material and the correlation between structure and observed properties. In addition to lectures, the PI will develop a lab manual, in consultation with an academic staff member, for a lab section to the proposed course. The lab manual will focus on simple and elegant experiments to observe the electronic and optical properties of polymers. The online archive of these experiments will be a unique resource for students and teachers of polymeric materials. Finally, an extended outreach program aimed at high school female students, minority colleges, and industry, will be developed to benefit a broader community.The broader impact of the proposal will be: (1) Education of materials engineers on the chemistry ofpolymeric materials. (2) Broader dissemination of research on nanostructured materials. (3) Bettermaterials science training of high school students and teachers. (4) Mentoring of female graduate and undergraduate students.

该提案描述了一个五年计划的综合研究，教育和推广纳米结构聚合物复合材料与电活性分子亚基。PI将她在嵌段共聚物合成/形态表征和电光材料设计方面的专业知识带到这项研究中。这两个专业领域在拟议的研究中相结合，允许PI开发一个综合研究计划，这将进一步推动她在纳米结构材料领域的职业生涯。纳米结构材料，如自组装嵌段共聚物或树状大分子，构成了一类独特的材料，在药物输送系统、纳米电子学、电光学和光子带隙材料中有着广泛的应用。所有这些应用的基本原则是将生物活性或电活性成分限制在特定的尺寸和形状内。例如，随着下一代高光电系数发色团和宽带调制器和光子移相器等原型器件的发展，电光聚合物领域在过去五年中经历了前所未有的增长。通过对发色团、聚合物主体和包层材料设计等因素的独立优化，实现了发色团的EO系数为100pm/V，聚合物主体的损耗小于0.1db/cm。然而，对发色团和聚合物宿主之间的界面的基本理解仍然难以捉摸。因此，利用发色团/聚合物界面在控制纳米形态和最终宏观EO活性方面代表了一个额外的、很大程度上未被探索的自由度。提出的研究计划的智力影响是通过化学和物理手段控制具有活性分子亚基的结构域的大小和形状。这些策略将用于合理设计纳米结构EO材料的具体案例，并且可以很容易地适用于其他含有共轭单元的材料。提出的工作的主要目标包括：a)通过设计界面改变通常不相容的发色团和聚合物宿主，设计裁剪纳米结构域的化学方法；b)利用嵌段共聚物相分离产生极化EO结构域的设计策略；c)形态学表征和光学测量，以建立功能纳米结构的结构-性能关系模型。前两个目标是通过化学手段控制活性纳米结构域的大小和形状，并直接进入第三个总体目标，即将形貌与观察到的活性联系起来。通过透射电子显微镜（TEM）和原位x射线衍射在直流电场下对所得形貌进行实验研究。研究职业规划与同样积极的教育和外展计划紧密结合，包括传统课程和广泛的指导。该项目将在威斯康星大学麦迪逊分校材料科学与工程系开设首个高分子课程《高分子材料》，主要侧重于纳米结构电子聚合物。本课程将通过教育材料工程师在聚合物材料的化学设计方面以及结构与观察到的性质之间的相关性来满足传统硬材料部门的需求。除了讲课外，PI还将与学术人员协商，为拟议课程的实验部分编写一份实验手册。该实验室手册将重点放在简单和优雅的实验，以观察聚合物的电子和光学性质。这些实验的在线档案将成为高分子材料学生和教师的独特资源。最后，一项针对高中女学生、少数民族学院和工业界的扩展外展计划将得到发展，以使更广泛的社区受益。该提案的更广泛影响将是：(1)材料工程师对聚合物材料化学的教育。(2)纳米结构材料研究的广泛传播。(3)加强高中学生和教师的材料科学培训。(4)女研究生、女本科生辅导。