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.
