Functional Block Copolymers as Guides for NanoparticleAssembly: Preparation of Cobalt Nanoparticles from Alkyne-Functional Polymers

技术综述：控制金属纳米颗粒在三维空间中的组织结构是纳米材料发展的一个重要目标，用于储能、光收集、催化和记忆存储等应用。实现这一目标的一条潜在途径包括利用嵌段共聚物经历微相分离的趋势，其中每个聚合物块占据主体材料中明确界定的空间区域。这种杂化材料的开发需要了解特定功能嵌段共聚物的合成和行为。通过这笔赠款，将继续努力通过受控合成炔基功能聚合物来控制纳米钴颗粒的有序性和结构。这项研究要解决的基本问题涉及了解如何控制炔功能嵌段共聚物的结构，从而控制钴(和其他)纳米颗粒的尺寸和形状。了解这些关系将指导后续的努力，以制备包含多种类型纳米粒子的聚合物-无机杂化材料。这些问题将通过构建选定的炔烃功能嵌段共聚物的文库，然后检查其相行为作为聚合物尺寸、组成和钴负载量的函数来解决。随后将考察这些变量对所得材料的磁性和聚合物-钴界面性质的影响。这些体系中的炔基功能聚合物在温和的条件下形成的物理交联会被用来控制纳米粒子表面功能化的程度。这项研究将进一步了解如何利用多嵌段共聚物将金属纳米颗粒结合到更大的组装中，并将促进这些材料的未来应用。非技术摘要：该项目旨在增加对如何使用专门设计的有机聚合物分子来控制纳米尺寸的金属颗粒如何聚集在一起形成更大的材料的理解，这些材料显示出有用的磁性、电学和光学性能。这种设计的材料在包括太阳能电池、电池、催化剂和记忆存储设备在内的一系列应用中具有巨大的潜力。本科生、研究生和博士后水平的研究人员将参与这项研究，并将在地方、地区和国家层面的科学会议上参与与公众交流他们的研究，包括新英格兰聚合物化学研讨会，这是一系列非正式的地区性会议，旨在让研究生有机会展示他们的研究。PI还将通过达特茅斯夏季充实(SEAD)计划，向资源不足的城市和农村高中的学生宣传大学和研究生水平的科学研究机会。

TECHNICAL SUMMARY:Controlling the organization of metallic nanoparticles in three-dimensional space is an important goal for the development of nanometer-scale materials for applications including energy storage, light harvesting, catalysis, and memory storage. One potential route to this goal involves the exploitation of the tendency for block copolymers to undergo micro-phase separation in which each polymer block occupies well-defined spatial regions in the bulk material. Development of such hybrid materials requires an understanding of the synthesis and behavior of specific functional block copolymers. Ongoing efforts to control ordering and structure of cobalt nanoparticles through controlled synthesis of alkyne-functional polymers will be continued through this grant. The fundamental questions to be addressed by this research relate to understanding how control over structure of alkyne-functional block copolymers can provide control over size and shape of cobalt (and other) nanoparticles. Understanding these relationships will guide subsequent efforts to prepare polymer-inorganic hybrids containing multiple types of nanoparticles.These issues will be approached through the construction of libraries of selected alkyne-functional block copolymers followed by an examination of their phase behavior as a function of polymer size, composition, and cobalt loading. The effects of these variables on the magnetic properties of the resulting materials and on the nature of the polymer-cobalt interface will subsequently be examined. The physical crosslinks that the alkyne-functional polymers in these systems form under mild conditions will be exploited to control the degree of nanoparticle surface functionalization. This research will further the understanding of how metallic nanoparticles can be incorporated into larger assemblies with the aid of multi-block copolymers and will facilitate future application of these materials. NON-TECHNICAL SUMMARY:This project aims to increase the understanding of how specifically-designed organic polymer molecules can be used to control how nanometer-sized metal particles come together to form larger materials that show useful magnetic, electronic, and optical properties. Such designed materials have great potential in a range of applications including solar cells, batteries, catalysts, and memory storage devices. Researchers at the undergraduate, graduate, and post-doctoral levels will be involved in this research and will participate in the communication of their research to the general public at scientific meetings at the local, regional, and national levels, including the New England Polymer Chemistry Workshop, an informal series of regional meetings designed to give graduate students the opportunity to present their research. The PI will also work through the Summer Enrichment at Dartmouth (SEAD) program to inform students from under-resourced urban and rural high schools about opportunities in scientific research at the college and graduate levels.