Controlled plasma-droplet interactions: Two-phase flow millifluidic system.

In this study, a well-defined and controlled plasma-droplet two-phase flow millifluidic system was developed. We established a detailed quantitative relationship among plasma discharge characteristics, flow dynamics, and the gas–liquid transport properties of reactive oxygen and nitrogen species (RONS). Under constant energy inputs, the gas–liquid contact area in the two-phase flow initially increases and subsequently decreases with rising liquid flow rates. Efficient gas–liquid transport results in a linear decrease in residual gaseous RONS and a corresponding linear increase in aqueous RONS, both of which align with changes in gas–liquid contact area. Notably, across various two-phase flow conditions, the combined values of residual gaseous RONS and liquid oxidation capacity consistently match the decreased plasma intensity due to droplet involvement in the discharge. The quantitative optimization of fluid characteristics and RONS transport within the two-phase flow millifluidic system significantly boosts the energy efficiency of Methyl Orange decolorization, far exceeding that of traditional methods. [ABSTRACT FROM AUTHOR]