Nanosecond Pulse Discharges at a Liquid-Vapor Interface and in Liquids: Discharge Dynamics and Plasma Chemistry

这项工作将研究等离子体，它是在接近室温的液体表面和液体中产生的电离气体的云或气泡。这类等离子体在生物和医学领域的几项新兴技术中具有巨大的发展潜力，这些技术用于去除水中的有机污染物、激活用于杀菌和消毒的水、伤口愈合、皮肤癌治疗、液体中纳米粒子的合成以及清洁能源技术。人们对这些等离子体中的基本物理和化学过程知之甚少，这主要是因为缺乏将在这项工作中获得的准确实验数据。这项研究的结果将加深我们对这些过程的理解，并有望对生物医学、医疗保健和清洁能源等低温等离子体的发展产生重大影响。我们将使用以下方法研究维持在液-汽界面上和在液体中的脉冲等离子体的基本动力学：(I)测量液-汽界面上表面电离波等离子体中的电场。这些数据将提供对表面电离波结构和动力学的洞察。(2)近表面等离子体中电子密度和电子温度的测量。这些数据将量化不同能量模式之间的输入能量分配。(3)近表面液层中溶剂化电子的测量。这些数据将显示电子是如何传输到液体表面并渗透到液体中的。这些测量还可能解决等离子体是否可以直接在液体中产生的根本问题。(4)测量气液界面附近等离子体中的物种数密度。这些结果将与动力学模型预测进行比较，以量化表面等离子体中电场和电子能量对气相等离子体化学的影响。这项工作将对实验数据很少的瞬变汽液界面等离子体的动力学和动力学进行定量的洞察，并使对其行为的可靠预测成为可能。

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.