Synthesis of Novel Al/CuO and Mg/CuO Core/Shell Nanoenergetic Materials and Study of their Fundamental Reaction and Ignition Characteristics

Energetic materials (EMs) including explosives, pyrotechnics, and propellants have found various civilian and military applications. Nanoenergetic materials (nEMs) have improved performance in energy release, ignition, and other properties compared to conventional EMs. This makes nEMs have promising applications in actuation, ignition, propulsion, power, welding, fluidic, and electro-explosive devices at the micro and nanoscale.This proposed project will synthesize novel core/shell nEMs with nano fuel as the core and nano oxidizer as the shell on a silicon substrate. The first step is to synthesize two kinds of nanoparticle seeds on a silicon substrate. As the initial work, the PI has synthesized well-separated CuO nanoparticles, which will be used as one kind of the seeds. The second step is to combine the nanoparticle seeds with glancing angle deposition to synthesize well-separated vertically aligned (or close to so) Al nanorods and Mg nanostructures as the fuels. The PI has synthesized vertically aligned Mg nanostructures, but they are not well-separated. The separation will be achieved by using the nanoparticle seeds in this project. The third step is to integrate CuO around the well-separated Al nanorods and Mg nanostructures by self-assembly to realize novel Al/CuO and Mg/CuO based core/shell nEMs. The fourth step is to systematically study the fundamental reaction and ignition characteristics of the novel nEMs including exothermic reaction, onset reaction temperature, activation energy, heat release, ignition power, ignition delay, and ignition energy.Compared to previous approaches, the novel nEMs have the advantages as follows: (1) the fuel core is protected by the stable oxidizer shell. Consequently, the nEMs are more resistant to the environment (e.g. moisture) and suitable for long term storage/usage; (2) the nEMs only contain nanoscale fuel/oxidizer (no microscale fuel/oxidizer exit), resulting in better mixing uniformity, enhanced contact, and improved performance; (3) the proposed synthesis methods are facile, low-cost, and also scalable.This project aims to provide the EMs community with novel nEMs that have improved performance including enhanced exothermic reactions and reduced ignition delay and energy. Especially, the nEMs are resistant to the environment and suitable for long term storage/usage, which is very desirable for many practical applications. Furthermore, the nanoscale core/shell structure will significantly improve the overall mixing and spatial uniformity of the nEMs and provide an ideal platform for scientific researchers to study the fundamental thermodynamic and kinetic properties of energetic materials.