Complex Functional Materials Accessed Uniquely through Selective Covalent and Non-covalent Macromolecular Interactions

技术概述：这项工作是基础性的，包括复杂纳米结构的合成和研究它们的超分子组装行为以及由此产生的复杂形态的性质。控制自由基聚合和开环聚合的组合将用于制备线性三嵌段三元聚合物和分子刷状三嵌段三元聚合物。每种聚合物的拓扑结构将包括至少一种半结晶聚合物成分，并且整体纳米结构将是两亲性的。将探讨它们在水中的超分子组装过程中发生的差异。一个重要的努力将指向确定分子拓扑结构对分子链包装和整体性能的影响，通过在选择性区域内交联来稳定组装，并挖掘部分纳米结构。通过这一过程，纳米约束和共价连接在聚合物链和交联网络表面之间的作用将通过结晶和熔化转变特性来探讨。主客体行为也将被研究，其中一个目标是有机-无机杂化材料，利用复杂的有机聚合物形态作为外壳层来包装小分子客体和磁性无机核心，以促进磁回收。表征研究将包括标准光谱技术，以确定成分（核磁共振，红外，紫外可见），尺寸和内部形态的测量（动态光散射，原子力显微镜，透射电子显微镜，小角中子散射，小角x射线散射），热性能分析（差示扫描量热法和热重分析），评估纳米颗粒的力学性能（石英晶体微天平耗散监测（QCM-D））和主客行为（紫外可见，高效液相色谱，QCM-D）。非技术概述：线性嵌段共聚物的超分子组装导致高性能材料，例如坚韧塑料，或用于医学成像和治疗的纳米设备。新的前沿领域将涉及由更高结构的聚合物构建复杂材料。研究合成聚合物的组成、大小、形状和结构对其在水中的受控聚集的影响，扩展了分子组装过程的基础知识，并有望在解决现实问题的应用中获得先进性能的纳米材料。最初的目标将是优化磁性纳米颗粒周围的有机聚合物涂层，作为基于隔离捕获和基于磁性回收环境中污染物的高容量材料。还可以预见到许多其他应用。所提议的工作的主要技术成果和更广泛的影响将是(1)多样化和广泛的教育，培训和招募下一代化学家，他们在合成有机/聚合物化学方面获得专业知识，特别是在材料科学和工程方面，(2)合成聚合物化学技术的进步，(3)创造有可能对社会产生积极影响的新材料。知识和专业知识的广度和深度将是广泛和跨学科的。所有层次的基础广泛的教育活动，包括为德克萨斯农工大学的化学家和工程师开发聚合物科学课程，以及基于网络的聚合物化学和纳米结构材料应用的远程教学课程，将在这项拨款支持的四年中继续进行。

TECHNICAL SUMMARY: The proposed work is of a fundamental nature, and includes the synthesis of intricate nanostructures and investigation of their supramolecular assembly behaviors and the properties of the resulting complex morphologies. Combinations of controlled radical polymerizations and ring opening polymerizations will be used to prepare linear triblock terpolymers and molecular brush triblock terpolymers. Each polymer topology will include at least one semi-crystalline polymer component and the overall nanostructures will be amphiphilic. The differences that occur during their supramolecular assembly in water will be explored. A significant effort will be directed toward determination of the effects of molecular topology on molecular chain packing and overall properties, with the assemblies being stabilized by crosslinking within selective domains, and with portions of the nanostructures being excavated. By this process, roles of nanoconfinement and covalent attachment between polymer chains and crosslinked network surfaces will be probed by the crystallization and melting transition characteristics. Host-guest behaviors will also be investigated, with one target being organic-inorganic hybrid materials that utilize the complex organic polymer morphology as a shell layer for packaging small molecule guests and magnetic inorganic cores to facilitate magnetic recovery. Characterization studies will include standard spectroscopic techniques to determine the compositions (nuclear magnetic resonance, infrared, ultraviolet-visible), measurement of dimensions and internal morphologies (dynamic light scattering, atomic force microscopy, transmission electron microscopy, small angle neutron scattering, small angle x-ray scattering), analysis of the thermal properties (differential scanning calorimetry and thermogravimetric analysis), evaluation of the nanoparticle mechanical properties (quartz crystal microbalance with dissipation monitoring (QCM-D)), and host-guest behaviors (UV-vis, high performance liquid chromatography, QCM-D).NON-TECHNICAL SUMMARY: The supramolecular assembly of linear block copolymers is leading to high performance materials, for instance tough plastics, or nanoscopic devices for medical imaging and therapy. The new frontier will involve the construction of complex materials from polymers of higher structure. The proposed investigation, of the effects of the compositions, sizes, shapes and architectures of synthetic polymers on their controlled aggregation in water, extends the fundamental knowledge of molecular assembly processes and is expected to lead to nanoscopic materials for advanced performance in applications that will solve real-world problems. An initial target will be optimized organic polymer coatings surrounding magnetic nanoparticles, to serve as high capacity materials for sequestration-based capture and magnetic-based recovery of pollutants in the environment. Many other applications can be anticipated. The primary technical outcomes and broader impacts of the proposed work will be (1) diverse and extensive education, training and recruiting of the next generation of chemists, who gain expertise in synthetic organic/polymer chemistry, with specialty in materials science and engineering, (2) advances in synthetic polymer chemistry techniques, and (3) creation of novel materials that have the potential to positively impact society. The breadth and depth of knowledge and expertise will be extensive and cross disciplinary. Broad-based educational activities, at all levels, including the development of polymer science courses for chemists and engineers at Texas A&M University, and web-based distance-taught courses on polymer chemistry and applications of nanostructured materials, will be continued throughout the four years of this grant support.