Designing composite energetic nanomaterials with tunable interfacial activities via laser ablation synthesis in solution
Abstract
Energetic nanomaterials (ENMs) find applications in solid state propellants and explosives. Yet, past works on energetic nano Al had revealed that the large heat release in these first generation ENMs were offset by hindered detonation rates due to the fuel oxidizer diffusion lengths and rates being compromised by excessive oxide shell formations and NP aggregations. Few efforts have attempted to tune their energetic behaviors by tailoring the surface structural rearrangements (onion like layers or nanocages) that lead to excessive internal stresses within the metallic cores. Yet, there exists weak fundamental understanding and considerable challenges in the rational design and synthesis of such nanostructured architectures. Apart from particle size and morphology, unwanted oxide layer on metal NPs itself shifts their oxidation mechanism from reaction limited to diffusion limited at later stages. To this end, carbon coatings on Al NPs facilitate safe handing while promoting enhanced activities due to the added advantages of the coating itself oxidizing into gaseous products (CO2, CO etc.) without any residual ash formation, while allowing the carbon shell to retard NP aggregations. But, the challenge remains in the facile yet, chemically clean synthesis of these encapsulated NPs without contaminating and-or oxidizing the metal cores. Here, we address this knowledge gap through rational design and structure property characterizations of metastable nanostructures with fullerene like surface layers encapsulating energetic metal-metalloid NPs cores in graphitic shells synthesized via laser ablation routes. Such nanostructures allow tailored design of interfacial structures that can either lead to strain energy manifestation or, rate controlled release of solid propellants under high pressure-temperature to prevent oxide shell mediated surface passivation. The immediate objective of the proposal will be to design, develop and deploy Al-C based ENMs
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- FA95501910366
Entities
People
- Dibyendu Mukherjee
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Tennessee