CAREER: Unique Nanostructured Materials from Molecularly Engineered Bottlebrush Copolymers

本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。这项CAREER资助支持的研究将集中在（1）多组分瓶刷共聚物的合成，（2）形状持久的瓶刷大分子的分子模板，以及（3）瓶刷嵌段共聚物的熔融相自组装。将活性自由基聚合和开环聚合技术相结合，合成具有定制化学结构的高级瓶刷共聚物。多组分瓶刷共聚物将被转化为具有明确定义的结构参数（长度、直径和孔径）和功能组成的独立的开放式管状纳米物体。瓶刷大分子支架将使得能够制备在自组装的热力学控制下无法获得的结构。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多功能的构建模块的纳米器件的制造和药物输送应用中的封装剂。二嵌段瓶刷共聚物的熔融自组装将被用于制备具有大畴间距和分级体系的周期性纳米结构材料。将利用一系列表征技术，包括超小X射线散射和透射电子显微镜，来研究这些大分子的熔融相行为。这项研究将有助于建立构成瓶刷共聚物的形状和他们的包装趋势之间的关系，这是一个必要的先决条件，在其基础上定制材料的制造。核-壳和其他先进的瓶刷共聚物将允许复杂的网络和复合结构的制造，这将是针对光子学和超滤应用。非技术总结纳米技术的承诺不能实现没有定制的材料，精确地在纳米长度尺度结构的可用性。本提案中所述的研究将提供获得新的聚合物纳米材料的途径，这些材料是任何其他方法都无法获得的，并且将在广泛的应用中具有潜在的实用性，例如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。这项研究计划支持的职业赠款将同时整合教育举措，以促进聚合物和纳米技术教育在布法罗地区。将为初中和高中教师组织纳米技术讲习班，为他们提供专业发展机会和内容增益。其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理解，并促进聚合物的使用，以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的伙伴关系将最大限度地影响代表性不足的少数民族和低收入学生。将通过为本科生提供研究机会和组织新生系列研讨会来促进本科层次的聚合物教育。

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.