Processing and Properties of Polymer-Grafted Nanoparticle Monolayers
Abstract
An integrated experimental and simulation approach will be used to examine polymer-grafted nanoparticle (PGN) structure and dynamics from molecular to film scale. Monolayer assemblies of PGNs will be used to investigate the particle spacing and mechanical-rheological properties as a function of particle size, graft density, polymer molecular weight, and solvent presence. Coarse-grained molecular dynamics simulations will be validated versus initial experimental results. Then they will be used to consider a variety of PGN architectures and analyze their conformations and entanglements in greater detail than is possible experimentally. In tandem with experimental results, this will show how chain conformation differences due to graft density, chain length, and solvent lead to differences in mechanical properties. Single-component PGNs overcome many of the limitations of traditional composites, such as ensuring particle dispersion. Thus, the ability to process these materials is key. For neat polymers, theory is well developed to predict material flow and viscoelastic properties. However, grafting chains to curved surfaces, such as nanoparticles, significantly changes the amount and location of entanglements in ways that are not fully understood. This work s main scientific contribution will be to show how polymer chain grafting to curved surfaces, with and without solvent and at varying graft lengths and graft densities, impacts the chain conformations, entanglements, and macroscopic mechanical properties. This understanding will impact design of tougher structural inorganic-organic hybrid materials and could lead to structurally robust membranes, solid dielectrics and electrolytes. It is also relevant to applications such as flow of hairy nanoparticles to create pre-ceramic materials, 3D printing of next-generation composites, and novel coatings on space platforms.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310288
Entities
People
- Daniel T Hallinan
Organizations
- Air Force Office of Scientific Research
- Florida A&M University
- United States Air Force