Brush Particle-Based Composites for Thermal Management Materials
Abstract
Thermal management is a key design parameter for multiple warfighter technologies. Electronic devices that generate heat require the development of coatings and interfaces that allow heat to be quickly dumped to the environment. Conversely, structures and personnel that require thermal camouflage to prevent detection via their thermal profile require their outermost layer to have low IR emissivity and significant thermal insulation. In each of these cases, the thermal properties must be balanced with multiple other criteria, such as low density or lightweight form factors, good mechanical stability, and the ability to be applied to multiple types warfighter equipment. Given this complex set of material characteristics, it is difficult to find a single material that meets all requirements. Composites consisting of homogenously dispersed inorganic nanoparticles embedded within a polymer matrix offer the opportunity to merge the characteristics of their constituent components to address this challenge: a percolating and continuous polymer network would provide ideal mechanical and processing characteristics, while large quantities of inorganic nanoparticles would significantly improve either IR absorption or thermal conductivity, depending on which particles are selected. However, inorganic fillers can normally be added to the polymer matrix in only small quantities (typically <20 vol%) before aggregating and compromising mechanical and transport properties. The critical need to improve these materials is a method to incorporate large quantities of inorganic particles into a polymer without sacrificing mechanical performance or permitting aggregation. Here we will develop crosslinkable polymer-coated nanoparticles (dubbed XNPs) capable of forming covalent bonds between polymer chains post-synthetically. XNPs can serve as single-component composite building blocks that completely prevent aggregation and improve mechanical performance, even at particle loadings of >50 vol%. Here we will synthesize solid state XNP composites for coatings that either enhance thermal dissipation or prevent IR emission, and perform fundamental investigations of how the synthesis and crosslinking of XNPs affect the final chemical, mechanical, and thermal properties of the composites.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 11, 2022
- Source ID
- W911NF2210215
Entities
People
- Robert J Macfarlane
Organizations
- Army Contracting Command
- Massachusetts Institute of Technology
- United States Army