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

第一部分：非技术总结有机聚合物材料，通常被认为是塑料，对人类生活的方方面面都至关重要，从我们穿的衣服到我们使用的电脑，再到我们开车的轮胎，再到给药的装置。由于聚合物的大分子尺寸，有很大的机会在整个分子框架或特定的子区域改变化学成分和结构，以实现材料性能的显著变化：即柔性与刚性、导电与绝缘等。随着聚合物的化学结构变得越来越复杂，它们的性能和技术应用也经常增加。拟议工作的预期意义将是促进合成化学方法的进步，这种方法允许简单、可扩展地生产具有复杂程度并表现出独特物理和机械性能的聚合物材料。人们的重点是将聚合物打造成一种“瓶刷式”的分子结构，使它们能够以预制的超大小大分子的形式存在，这些大分子包含为程序化组装或降解而设计的亚区。然后，从这些大分子可以生产出功能纳米结构的物体。这样的物体可能被用作合成疫苗的病毒的合成版本，或者用作水净化、气体分离或其他运输和分离应用的多孔薄膜。其他目标结构将包括能够通过磁回收清理漏油的纳米结构。产生的基础知识预计将影响化学、物理和工程学科，该项目还将包括多方面的教育内容。随着这些新材料的实际适用性，包括待研究的特定目标应用，可以预期工业兴趣，这可能转化为提供更多社会效益的产品。第2部分：技术总结拟议工作的活动将涉及开发先进的合成方法，以提供具有增强的组成、结构和功能的纳米材料。一个目标是通过首先动力学地将线性聚合物前体捕获到具有预定区域化学分布的官能团的共价分子刷结构中来增加材料组成、结构和性能的复杂性。第二个目标是了解通过在溶液、薄膜和块体中组装所得到的分子刷构建块可以产生的形貌和性质。除了分子结构对组装过程和所产生的性质的作用外，多肽片段将被合并为侧链嫁接，以提供活跃的二级结构相互作用，并且将内置可降解的多肽或聚磷酸酯部分，以允许对整个材料的纳米域内的密度进行异质调制。除了基本目标之外，具体目标将包括模仿球形蛋白组装成病毒衣壳的离散纳米笼框架，以及扩展的薄膜或大块多孔聚合物网络材料，每种材料的尺寸和孔隙率都受到控制，可能用于运输和分离应用。另一个目标是进一步研究无机-有机杂化异质结构，旨在超越我们最近开发的磁性壳交联类捏合体(MSCK)纳米颗粒，使其在原油开采方面的能力更胜一筹。将采用的方法包括聚合和化学修饰反应的组合来建立结构，均相或多相超分子组装方法来提供复杂的形态，选择性区域的交联来稳定这些形态，在某些情况下，材料中的选择性区域的降解。在整个工作过程中，将进行严格的定性研究。广泛的教育和外展计划是该项目的一部分。

PART 1: NON-TECHNICAL SUMMARYOrganic polymer materials, commonly thought of as plastics, are of critical importance to every aspect of human life, from the clothes that we wear to the computers that we use to the tires on which we drive to the devices through which medicines are administered. Due to the large, macromolecular size of polymers, there is great opportunity to vary the chemical composition and structure, throughout the entire molecular framework or in specific sub-regions, to achieve significant variation in the materials properties: i.e., flexible vs. rigid, conducting vs. insulating, etc. As the chemical structure of polymers becomes increasingly complex, their properties and technological applications also often increase. The expected significance of the proposed work will be in the advancement of synthetic chemistry approaches that allow for simple, scalable production of polymer materials that possess intricate complexity and exhibit unique physical and mechanical properties. A focus is on building the polymers to have a "bottle-brush-like" molecular architecture enabling them to exist as pre-fabricated super-size macromolecules that contain sub-regions designed for programmed assembly or degradation. From these macromolecules functional nanostructured objects can then be produced. Such objects may be able to be used as synthetic versions of viruses for synthetic vaccines, or as porous thin films for water purification, gas separation or other transport and separations applications. Other target structures will include nanostructures that are capable of oil spill clean-up with magnetic recovery. The fundamental knowledge generated is expected to impact chemistry, physics and engineering disciplines, and the project will also include multifaceted educational components. With the practical applicability of these new materials, including the specific target applications to be studied, industrial interest may be anticipated, which may translate to products offering additional societal benefits.PART 2: TECHNICAL SUMMARYThe activities of the proposed work will involve the development of advanced synthetic methodologies to afford nanoscopic materials having enhanced compositions, structures and functions. One objective is to increase the complexity of materials compositions, structures and properties, by first kinetically-trapping linear polymer precursors into covalent molecular brush architectures having pre-determined regiochemical distributions of functionalities. A second objective is to develop an understanding of the morphologies and properties that can be generated from the assembly of the resulting molecular brush building blocks in solution, thin films and the bulk. In addition to the roles of molecular architecture on the assembly processes and resulting properties, polypeptide segments will be incorporated as side chain grafts to provide for active secondary structural interactions, and degradable polypeptide or polyphosphoester portions will be built-in to allow for heterogeneous modulation of the density within nanoscopic domains of the overall materials. Beyond the fundamental objectives, specific targets will include discrete nanocage frameworks, modeled after the assembly of globular proteins into viral capsids, and extended thin-film or bulk porous polymer network materials, each of controlled dimensions and porosities for potential use in transport and separations applications. An additional objective is to further investigate hybrid inorganic-organic heterostructures that are designed to outperform our recently-developed magnetic shell crosslinked knedel-like (MSCK) nanoparticles in their capacity for crude oil recovery efforts. The methods that will be employed will include combinations of polymerization and chemical modification reactions to build up the structures, homogeneous or heterogeneous supramolecular assembly methods to afford complex morphologies, crosslinking of selective regions to stabilize those morphologies, and, in some cases, degradation of selective domains within the materials. Throughout the work, rigorous characterization studies will be conducted. A broad educational and outreach program is part of this project.