This work will study plasmas, which are clouds or bubbles of ionized gas, produced near liquid surfaces and in liquids at near room temperatures. Such plasmas have significant potential for development of several emerging technologies in biology and medicine for removal of organic contaminants from water, activation of water for sterilization and disinfection, wound healing, skin cancer therapies, synthesis of nanoparticles in liquids, as well as clean energy technologies. Fundamental physical and chemical processes in these plasmas are poorly understood, primarily due to lack of accurate experimental data which will be obtained in this work. The results obtained during this study will improve our understanding of these processes and are expected to have a major impact on development of low-temperature plasmas for biomedical applications, healthcare, and clean energy.
Fundamental kinetics of pulsed plasmas sustained at a liquid-vapor interface and in liquids will be studied using the following methods: (i) Measurements of electric field in surface ionization wave plasmas at a liquid-vapor interface. These data will provide insight into surface ionization wave structure and dynamics. (ii) Measurements of electron density and electron temperature in the near-surface plasma. These data will quantify input energy partition among different energy modes. (iii) Measurements of solvated electrons in the near-surface liquid layer. These data will show how electrons are transported to the liquid surface and penetrate into the liquid. These measurements may also resolve the fundamental question whether the plasma may be generated directly in the liquid phase. (iv) Measurements of species number densities in the plasma near the liquid-vapor interface. These results will be compared with kinetic modeling predictions to quantify the effect of electric field and electron energy in the surface plasma on vapor phase plasma chemistry. This work will yield quantitative insight into dynamics and kinetics of transient liquid-vapor interface plasmas for which there is little experimental data, and make possible confident prediction of their behavior.
