CAREER: Nanocomposite Structure Control via Nanoparticle Self-Assembly

马萨诸塞州理工学院的Robert J. Macfarlane教授得到了化学系大分子、超分子和纳米化学（MSN）项目以及材料研究系固态和材料化学（SSMC）项目的支持，以开发由聚合物接枝纳米颗粒组成的纳米复合材料构件。 这些结构单元能够通过分子相互作用组装成有序结构，因此可以用于合成具有可控物理性能的新型复合材料。 该项目提供了一个新的框架，用于控制多个长度尺度的材料结构，通过设计生成材料，用于从能量收集和存储到传感技术的应用。该项目的相关教育计划侧重于建立一个外展计划，为社区学院的教育工作者和学生提供研究经验。 其目标是促进学生参与尖端研究技术，并为STEM领域的未来职业生涯提供途径。 在这个项目中，纳米复合材料构建块（所谓的纳米复合材料tectons，NCT）被开发并用于同时在原子，纳米和宏观长度尺度上操纵新材料的结构和组成。NCT由聚合物接枝的纳米颗粒组成，其中每个聚合物链终止于能够超分子键合的官能团。 调节NCT的键合相互作用允许纳米颗粒超晶格的定向组装。 影响自组装过程的各种设计参数（如颗粒大小，形状和组成，聚合物组成和长度，超分子基团身份，溶剂和基质）进行了研究。 此外，与NCT组装的热力学和动力学参数进行了测定。 其目标是组装聚合物-纳米颗粒复合材料，其纳米级结构诱导独特的光学现象，如光子带隙或耦合等离子体共振。

Professor Robert J. Macfarlane of the Massachusetts Institute of Technology is supported by the Macromolecular, Supramolecular, and Nanochemistry (MSN) program of the Division of Chemistry and the Solid State and Materials Chemistry (SSMC) program in the Division of Materials Research to develop nanocomposite building blocks composed of polymer grafted nanoparticles. These building blocks are capable of assembling into ordered structures via molecular interactions, and may therefore be used to synthesize new composite materials with controllable physical properties. The project provides a new framework for controlling material structure across several length scales, generating materials by design for applications ranging from energy harvesting and storage to sensing technologies. The associated educational plans of the project focuses on the establishment of an outreach program to provide research experiences for community college educators and students. The goals are to promote the involvement of students in cutting edge research techniques and to provide a pathway to future careers in STEM fields. In this project, nanocomposite building blocks (so called nanocomposite tectons, NCTs) are developed and used to manipulate the structure and composition of new materials at the atomic, nano, and macroscopic length scales simultaneously. NCTs consist of polymer grafted nanoparticles, where each polymer chain terminates in a functional group capable of supramolecular bonding. Tuning of the bonding interactions of the NCTs allows for the directed assembly of nanoparticle superlattices. The various design parameters which influence the self-assembly process (such as particle size, shape and composition, polymer composition and length, supramolecular group identity, solvent and matrix) are investigated. Furthermore, the thermodynamic and kinetic parameters associated with NCT assembly are determined. The goal is to assemble polymer-nanoparticle composites whose nanoscale structure induces unique optical phenomena such as photonic band gaps or coupled plasmon resonances.