CAREER: Nanocomposite Structure Control via Nanoparticle Self-Assembly

麻省理工学院的罗伯特·J·麦克法兰教授在化学部的高分子、超分子和纳米化学(MSN)计划以及材料研究部的固态和材料化学(SSMC)计划的支持下，开发由聚合物接枝纳米颗粒组成的纳米复合材料构建块。这些构件能够通过分子相互作用组装成有序结构，因此可以用来合成物理性能可控的新型复合材料。该项目为控制几个长度尺度的材料结构提供了一个新的框架，通过设计产生材料，应用范围从能源收集和存储到传感技术。该项目的相关教育计划侧重于建立一个外展计划，为社区大学教育工作者和学生提供研究经验。目标是促进学生参与尖端研究技术，并为未来在STEM领域的职业生涯提供一条途径。在这个项目中，开发了纳米复合材料构建块(所谓的纳米复合材料构件，NCTs)，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，每个聚合物链末端都有一个能够超分子成键的官能团。NCT的成键相互作用的调节允许定向组装纳米颗粒超晶格。研究了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、超分子基团同一性、溶剂和基质)。此外，还确定了与NCT组装相关的热力学和动力学参数。我们的目标是组装聚合物-纳米颗粒复合材料，其纳米级结构可以诱导出独特的光学现象，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.