Transport of cold plasma reactive species into water and bio-relevant effects of plasma-activated water
Machala Z., Hassan M. E., Mentheour R., Jankovič R., Štípala P., Hensel K., Janda M. 24th Symposium on Applications of Plasma Processes and 13th EU-Japan Joint Symposium on Plasma Processing SAPP XXIV, Štrbské Pleso (Slovakia), Jan 27- Feb 1, p. 21 (2023)
požiadaj o kópiu
|
Abstrakt: Atmospheric air plasma produces a cocktail of reactive oxygen and nitrogen species (RONS) with multiple functions. The transport of RONS to the liquid phase through plasma–liquid interface can be significantly enhanced by converting bulk water to aerosol microdroplets. The expected solubility
of various RONS does not fully match Henry’s law solubility coefficients. We verified the applicability of Henry’s law coefficients under strongly nonequilibrium conditions characteristic of plasma–liquid
interaction, with water in the form of bulk vs. microdroplets. This fundamental understanding can lead to optimized designs of plasma–water interaction systems for multiple applications in biomedicine,
environment, and agriculture.
Figure 1 shows the schematic diagram of elementary processes of ionization, excitation and dissociation in air plasma, and formation of radicals and other RONS, and their mutual reactions in the gas phase.
Then it shows their transport into the liquid water based on their solvation, indicating the Henry’s law coefficients. Finally, in the liquid, the plasma-formed, as well as the new ionic RONS diffuse and
undergo further reactions. The RONS transport processes in water are compared in the bulk and in two types of microdroplets, charged microdroplets produced by electrospray (ES), and nebulized noncharged
microdroplets. The amount of H2O2(aq) and NO3¯(aq) (mainly from gaseous HNO3) dissolved in the nebulized microdroplets was ~1 order of magnitude higher compared to that in the ES microdroplets because it was enhanced by their smaller size, providing larger plasma–water interface area. On the other hand, the production of NO2¯(aq) (mainly from HNO2 [2]) is higher in the charged ES microdroplets, which indicates the importance of the charge effects.
|