Systems Materials Design of Ordered Nanocomposite Assemblies

The ability to precisely organize matter across multiple length scales is a central challenge in modern materials science. In this dissertation, I develop a systems materials design approach to engineer hierarchically structured nanocomposite assemblies, integrating molecular recognition, supramolecular chemistry, colloidal assembly, and bulk processing into unified material platforms. At the molecular and nanoscale, I investigate how multivalent supramolecular interactions can be rationally programmed by controlling the architecture of polymer binders grafted to nanoparticle surfaces. Through systematic variations in polymer topology, recognition group density, and scaffold geometry, I demonstrate how polymer design dictates the thermodynamic strength and multivalency of nanoparticle superlattice assembly, enabling precise control of thermal stability, crystallographic symmetry, and collective bonding behaviors in massively multivalent systems. Building on these design principles, I develop a colloidal metallurgy framework to process selfassembled nanoparticle superlattices into dense macroscopic polycrystalline solids while preserving nanoscale order. By systematically studying the interplay of temperature, pressure, and time during colloidal sintering, I elucidate mechanisms of densification, defect evolution, and grain growth unique to colloidal systems, establishing processing–structure relationships that parallel but fundamentally diverge from atomic sintering. Finally, I extend these concepts to create stretchable nanocomposite supercrystals, embedding supramolecularly assembled superlattices into elastomeric matrices via co-engineered polymer chemistries that enable hierarchical strain transduction. These materials combine the nanoscale precision of supercrystals with mechanical robustness, reconfigurability, and stimuli-responsive optical properties, illustrating a scalable pathway to multifunctional metamaterials. Collectively, this work demonstrates how a systemslevel integration of molecular design, colloidal assembly, and bulk processing enables new paradigms for the synthesis of hierarchically ordered, functional nanocomposites.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Materials Science and Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2025

Author dc:creator

• Thrasher, Carl James

Advisors dc:contributor.advisor

• Macfarlane, Robert J.
• Hart, A. John

Statement dc:rights

• In Copyright - Educational Use Permitted
• Copyright retained by author(s)

Licence dc:rights.uri

• https://rightsstatements.org/page/InC-EDU/1.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/164501

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/164501