CAREER: Unique Nanostructured Materials from Molecularly Engineered Bottlebrush Copolymers

技术概述：该项目的目标是利用具有瓶刷结构的密集接枝共聚物来制造具有精确结构和功能控制的纳米多孔物体和纳米结构材料。由CAREER基金支持的研究将集中在(1)多组分瓶刷共聚物的合成，(2)形状持久瓶刷大分子的分子模板化，以及(3)瓶刷嵌段共聚物的熔融相自组装。先进的瓶刷共聚物量身定制的化学框架将通过结合活自由基和开环聚合技术合成。多组分瓶刷共聚物将转化为具有明确结构参数（长度、直径和孔径）和功能成分的独立开放式管状纳米物体。瓶刷式大分子支架可以制备在自组装热力学控制下无法实现的结构。分子设计将扩展到制备径向两亲性纳米管和刺激响应分子笼。所制备的纳米结构将作为制造纳米器件的通用构件，并作为药物递送应用中的封装剂。研究了双嵌段瓶刷共聚物的熔融相自组装，以制备具有大域间距和分层体系的周期性纳米结构材料。一系列表征技术，包括超小x射线散射和透射电子显微镜，将被用于研究这些大分子的熔融相行为。本研究将有助于建立瓶刷共聚物组分的形状与其堆积倾向之间的关系，这是在其基础上制造定制材料的必要前提。核壳共聚物和其他先进的瓶刷共聚物将允许制造复杂的网络和复合结构，其目标是光子学和超滤应用。非技术总结纳米技术的前景是无法实现的，没有可用的定制材料，精确地在纳米长度尺度结构。本提案中描述的研究将提供任何其他方法无法获得的新型聚合物纳米材料的途径，并且将在纳米器件和纳米电子学，药物输送，光子学和通信以及水净化等广泛应用中具有潜在的实用性。由CAREER基金支持的研究项目将同时整合教育举措，以促进布法罗地区的聚合物和纳米技术教育。为初中和高中教师举办纳米技术研讨会，为他们提供专业发展机会和内容收获。目的是提高公众对聚合物材料及其对纳米技术和其他先进应用的影响的认识和欣赏，并推广使用聚合物来加强一般的科学和技术教育。与纽约州最贫穷的城市学区布法罗公立学校（Buffalo Public Schools）合作，将最大限度地影响未被充分代表的少数族裔和低收入学生。通过为本科生提供研究机会和组织新生系列研讨会，促进本科阶段的聚合物教育。

TECHNICAL SUMMARYThe goal of this project is to utilize densely grafted copolymers with bottlebrush architecture for the fabrication of nanoporous objects and nanostructured materials with exact structural and functional control. The research supported by this CAREER grant will focus on (1) the synthesis of multi-component bottlebrush copolymers, (2) molecular templating of shape-persistent bottlebrush macromolecules, and (3) melt-phase self-assembly of bottlebrush block copolymers. Advanced bottlebrush copolymers with tailored chemical framework will be synthesized by a combination of living radical and ring-opening polymerization techniques. Multi-component bottlebrush copolymers will be converted to standalone open-end tubular nanoobjects with well-defined structural parameters (length, diameter and pore size) and functional composition. The bottlebrush macromolecular scaffold will enable the preparation of structures otherwise unattainable under thermodynamic control of self-assembly. The molecular design will be expanded to prepare radially amphiphilic nanotubes and stimuli-responsive molecular cages. The prepared nanostructures will serve as versatile building blocks for the fabrication of nanodevices and as encapsulating agents in drug delivery applications. Melt-phase self-assembly of diblock bottlebrush copolymers will be investigated for the preparation of periodic nanostructured materials with large domain spacings and hierarchical systems. An array of characterization techniques, including ultra-small X-ray scattering and transmission electron microscopy, will be utilized to study melt phase behavior of these macromolecules. This research will help to establish the relationships between the shape of constituent bottlebrush copolymers and their packing tendencies, which is an essential prerequisite for the fabrication of tailored materials on their basis. Core-shell and other advanced bottlebrush copolymers will allow for the fabrication of complex network and composite structures, which will be aimed for photonics and ultrafiltration applications.NON-TECHNICAL SUMMARYThe promise of nanotechnology cannot be realized without the availability of tailored materials that are precisely structured at the nanometer length scale. The research described in this proposal will provide access to new polymeric nanomaterials that are not attainable by any other methods and that will be of potential utility in a wide array of applications, such as nanodevices and nanoelectronics, drug delivery, photonics and communications, and water purification. The research program supported by this CAREER grant will simultaneously integrate educational initiatives to promote polymer and nanotechnology education in the Buffalo area. Nanotechnology workshops will be organized for middle and high school teachers to provide them with professional development opportunities and content gain. The aim is to increase public awareness and appreciation of polymeric materials and their impact on nanotechnology and other advanced applications, and promote the use of polymers to enhance science and technology education in general. The partnership with Buffalo Public Schools, the poorest urban school district in New York State, will maximize the impact on underrepresented minorities and low-income students. Polymer education at the undergraduate level will be promoted by providing research opportunities for undergraduate students, and by organizing freshman seminar series.