CAREER: Complex Hierarchical Self-Assembly Templated by Block Copolymers: Phase Structures, Nano Fabrication and Nano-Electrooptic Properties

职业：以嵌段共聚物为模板的复杂分层自组装：相结构、纳米制造和纳米电光特性

• 批准号: 0239415
• 负责人: Christopher Li
• 金额: $ 40万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0239415&HistoricalAwards=false
• 关键词: CAREER; Complex; Hierarchical; Self; Assembly

Hierarchical self-assembly is an essential part of nanotechnology and it offers one of the few practical strategies for making ensembles of nanostructures. Structure complexity in the hierarchical structures is of particular importance since it provides a practical means to combine different functionalities within a single material. The aim of this CAREER development plan is to achieve complex hierarchical self-assembled structures via combining two-dimensional (2-D) liquid crystalline (LC) ordering and block copolymer microphase separation process. The proposed research activities include: (1) Design, synthesize, and systematically investigate a series of bent-core liquid crystalline (BCLC) diblock copolymers in order to achieve novel complex hierarchical structures including LC columnar phase (Col) in block copolymer lamella (Col-in-Lam), Col in cylinder (Col-in-Cyl) and Col in sphere (Col-in-Sph) structures, etc. (2) Fabricate well-defined nano building blocks (such as nano porous plates, rods, spheres, etc.) using these hierarchically self-assembled diblock copolymers as templates. (3) Explore the nano-electrooptic properties of these novel hierarchical structures. Unique lamellar thickness controlled ferro-antiferroelectric properties will be realized in the proposed diblock copolymer system. Electric field tunable nanostructures will also be investigated. The proposed research will, for the first time, incorporate 2-D LC ordering into the ordered nanospace created by block copolymer microphase separation. The resulting hierarchical structures possess complex natures at both 1-5 nm and 10-100 nm length scales. From a scientific point of view, this system provides a unique opportunity to explore the complex phase geometry, small phase size and large interface effects on LC as well as block copolymer phase behaviors. LC phase stability might be altered in these small environments and novel phase structures might be generated. From the technological point of view, the hierarchical structures could be used as templates for nano fabrication applications. Well-correlated structures at different length scales might also provide a solution for the transfer of the novel properties at the nanoscale into a higher length scale. Furthermore, these hierarchical structures can serve as a scaffold for further nanoscience and nanotechnology research, particularly for nano device manufacturing due to their specific structure complexity. The structural complexity and hierarchies might also hold the key to designing synthetic materials that can mimic the elegant living systems. The educational component of the proposed CAREER development plan includes (1) Address the needs for the education of modern developments in polymer nanoscience and nanotechnology by developing a new course entitled Polymers and Nanotechnology. (2) Involve high school students and teachers, particularly under-represented populations, in the proposed polymer nanotechnology research activities. (3) Develop long-term collaborations between the PI's laboratory and industry through Drexel's Co-op system. These proposed education activities impose a broader impact. First, the proposed plan will help to bridge the existing gap between levels of educational developments by involving high school students and teachers in research activities through a number of mentorship programs. Secondly, due to the high population of under-represented groups in the Philadelphia region, the proposed out-reach program will be specifically geared towards encouraging the participation of under-represented populations. Thirdly, the proposed research results will be widely disseminated through publications in scientific journals, product development resulting from collaborations with industry and, as a natural outgrowth of gained knowledge resulting from involvement in research activities, more highly trained secondary education teachers. Lastly, through the establishment of collaborations with national laboratories and school districts in the surrounding Philadelphia region, the proposed plan will dramatically enhance the infrastructure for research and education. Combined with the "start-up package" supplied by Drexel University, the proposed plan will also enable the PI to establish a state-of-the-art polymer characterization center that will benefit both Drexel University and nearby industry.

分级自组装是纳米技术的重要组成部分，它提供了为数不多的实用策略之一，使合奏的纳米结构。分级结构中的结构复杂性是特别重要的，因为它提供了在单一材料中组合联合收割机不同功能的实用手段。该CAREER开发计划的目的是通过结合二维（2-D）液晶（LC）有序化和嵌段共聚物微相分离过程来实现复杂的分级自组装结构。拟议的研究活动包括：（1）设计、合成并系统研究了一系列嵌段液晶（BCLC）双嵌段共聚物，以获得嵌段共聚物片层中包含液晶柱相（Col）的新型复杂分级结构（Col-in-Lam），Col in cylinder（Col-in-Cyl）和Col in sphere（Col-in-Sph）结构等。（2）制造定义明确的纳米构建块（例如纳米多孔板、棒、球等）使用这些分级自组装的二嵌段共聚物作为模板。(3)探索这些新的层次结构的纳米电光特性。独特的层状厚度控制的铁-反铁电性能将实现在建议的双嵌段共聚物系统。电场可调纳米结构也将进行研究。拟议的研究将首次将2-D LC有序化纳入由嵌段共聚物微相分离产生的有序纳米空间中。所得到的分级结构在1-5 nm和10-100 nm的长度尺度下都具有复杂的性质。从科学的角度来看，该系统提供了一个独特的机会，探索复杂的相几何形状，小相尺寸和大界面的LC以及嵌段共聚物的相行为的影响。LC相稳定性可能会改变，在这些小的环境和新的相结构可能会产生。从技术的角度来看，分级结构可以用作纳米制造应用的模板。不同长度尺度下的良好相关结构也可能为将纳米级的新特性转移到更高的长度尺度提供解决方案。此外，这些分层结构可以作为进一步的纳米科学和纳米技术研究的支架，特别是由于其特定的结构复杂性，用于纳米器件制造。结构的复杂性和层次结构也可能是设计能够模仿优雅生命系统的合成材料的关键。拟议的职业发展计划的教育部分包括：（1）通过开发一门名为聚合物和纳米技术的新课程，满足聚合物纳米科学和纳米技术现代发展教育的需求。(2)让高中学生和教师，特别是代表性不足的人群参与拟议的聚合物纳米技术研究活动。(3)通过德雷克塞尔的合作系统，在PI的实验室和行业之间建立长期合作关系。这些拟议的教育活动产生了更广泛的影响。首先，拟议的计划将有助于弥合教育发展水平之间的现有差距，通过一些导师计划让高中学生和教师参与研究活动。其次，由于费城地区代表性不足的群体人口众多，拟议的外联方案将专门针对鼓励代表性不足的群体的参与。第三，拟议的研究成果将通过在科学期刊上发表文章、与工业界合作开发产品以及作为参与研究活动所获得知识的自然结果，通过更多训练有素的中学教师得到广泛传播。最后，通过与费城周边地区的国家实验室和学区建立合作，拟议的计划将大大加强研究和教育的基础设施。与德雷克塞尔大学提供的“启动包”相结合，拟议的计划还将使PI能够建立一个最先进的聚合物表征中心，这将有利于德雷克塞尔大学和附近的工业。