Expérimental
The portable, on-demand, and point-of-use (POP) synthesis of nanoparticles (NP) can improve the feasibility of mobile applications requiring such materials. For exam-ple, research in nanoenergetic materials includes using NP in liquid fuels to reduce pol-lutant emissions such as CO2. For electric propulsion in space, NP have been explored as alternative propellants. Conventional techniques for NP synthesis generally operate at local thermodynamic equilibrium (LTE) and are not appropriate for POP NP synthesis. However, fast, efficient, finely-controlled synthesis using a simple and compact platform may be possible with nanosecond repetitively pulsed (NRP) discharges that initiate non-LTE chemistry to promote nucleation and growth. This project will seek to demonstrate the efficacy NRP discharges for NP synthesis and develop a detailed, quantitative understanding of the synthesis mechanism. These goals will be achieved by linking the properties of the plasma, the products, and the reactive medium through tightly coordinated experiments centered on in situ laser diagnostics of spatio-temporal NP growth by using spontaneous Raman spectroscopy and coherent anti-Stokes Raman spectroscopy, as well as optical emission spectroscopy to determine plasma properties. Finally, we will develop a detailed, quantitative model of NP growth, which may involve molecular dynamics simulations or theoretical modeling.