CAREER: Directed Self-Assembly of Block Copolymers by High Magnetic Fields

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。技术概述：该提案概述了一个以利用磁场定向自组装嵌段共聚物（bcp）为中心的5年计划，并使用排列材料作为合成半导体纳米线的模板。今天好吗?材料科学是建立在能够在多个长度尺度上控制物质结构的基础上的。冶金学和陶瓷科学的历史说明了这种能力的演变，直到今天？S体和薄膜单晶生长工艺。相比之下，聚合物科学的发展轨迹还处于萌芽阶段——令人惊讶的是，目前仍缺乏实际的、可扩展的、可控制晶粒尺寸和取向的bcp处理方法。这些能力的缺乏阻碍了利用功能性bcp和纳米复合材料（如非线性光学材料、膜和光伏）的自组装的新技术的发展。这一建议直接解决了上述差距。它采用了一种新颖的定向自组装方法，通过使用专用仪器使用高磁场来对分层有序聚合物体系中的取向动力学进行关键的原位研究。它需要基于自组装微域之间的定制界面来合理设计材料，并使用大面积薄膜模板来合成垂直排列的纳米线，作为实现理想光伏几何形状的一步。目标是：(1)合理设计、合成和表征用于场对准的模型液晶（LC） bcp；(2)通过原位散射和离地显微镜技术定量研究材料的温度和场相关取向；(3)在宏观场取向BCP薄膜中合成化合物半导体CdS和ZnS。非技术总结：提出的工作将有助于在诸如光伏、非线性光学和膜等领域的新兴技术解决方案。它专门针对可用于下一代太阳能电池的半导体材料的生产。该项目将包括与国家实验室，国家高磁场实验室的互动，通过学生和PI的访问。指导学生研究人员是该提案的重要组成部分。特别是，所有得到支助的学生积极参与当地、区域和国家的科学界将是他们训练的一个组成部分，并将加强他们终身学习的愿望。提出的工作形式的基础上，一个新的教学和推广推力由PI以高分子材料科学为中心。一个新的课程，聚合物物理，其中包括一个实验室模块将继续由PI提供。该项目将面向社区的初中和高中学生，以及耶鲁大学代表性不足的学生。通过与纽黑文科学博览会的合作，为当地高中科学教师提出了一个新的暑期研究项目。总的影响是：(1)基础科学的发展与太阳能电池的应用；(2)材料科学、高分子科学本科、研究生教育；(3)新材料/高分子科学课程的开发；(4)加强中学生和教师的材料科学培训；(5)在本科和研究生阶段招募和指导代表性不足的群体；(6)新研究人员在各个层面与他们所在的科学共同体紧密结合。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).TECHNICAL SUMMARY:This proposal outlines a 5-year plan centered on the directed self-assembly of block copolymers (BCPs) using magnetic fields, and the use of aligned materials as templates for the synthesis of semiconducting nanowires. Today?s materials science is predicated on the ability to control the structure of matter on multiple length scales. The history of metallurgy and ceramic science illustrate the evolution of this capability through to today?s bulk and thin film single crystal growth processes. The trajectory in polymer science is nascent by comparison - surprisingly, practical and scalable methods for processing BCPs with controlled grain size and orientation are still lacking. The absence of these capabilities hampers the development of new technologies that harness the self-assembly of functional BCPs and nanocomposites such as in non-linear optical materials, membranes and photovoltaics. This proposal directly addresses the above mentioned gap. It takes a novel approach to directed self-assembly via the use of high magnetic fields using a dedicated instrument to conduct critical in-situ studies of alignment dynamics in a hierarchically ordered polymer system. It entails rational design of materials based on tailoring interfaces between self-assembled microdomains and pursues the synthesis of perpendicularly aligned nanowires using large-area thin film templates as a step towards the realization of ideal photovoltaic geometries. The objectives are: (1) Rational design, synthesis and characterization of model liquid crystalline (LC) BCPs for field alignment; (2) Quantitative studies of temperature and field-dependent alignment of materials via in-situ scattering and ex-situ microscopy; (3) Synthesis of compound semiconductors CdS and ZnS within macroscopically field-aligned BCP films. NON-TECHNICAL SUMMARY:The proposed work will contribute to emerging technology solutions in fields such as photovoltaics, non-linear optics and membranes. It specifically takes aim at the production of semiconducting materials which can be used for next generation solar cells. The project will include interactions with a national lab, the National High Magnetic Field Lab, via visits by students and the PI. Mentoring student researchers is an important component of this proposal. In particular, active participation of all supported students in the community of science locally, regionally and nationally will be an integral part of their training and will strengthen their desire for lifelong learning. The proposed work forms the basis for a new teaching and outreach thrust by the PI centered on polymer materials science. A new course on Polymer Physics which includes a lab module will continue to be offered by the PI. The PI will engage in outreach targeting middle and high school students at the community level, and under-represented students at Yale. Through partnership with the New Haven Science Fair, a new summer research program for local high school science teachers has been proposed. The impacts overall are: (1) Development of fundamental science with applications in solar cells; (2) Education of undergraduate and graduate students in materials science and polymer science; (3) Development of new materials/polymer science curriculum; (4) Improved materials science training of middle-high school students and teachers; (5) Recruitment and mentoring of underrepresented groups at the undergraduate and graduate level; (6) Strong integration of new researchers into their science community at all levels.