(128c) Generation of Oxidative Chemistries By Cold-Atmospheric Plasma

Devices to produce non-thermal (â??coldâ?) atmospheric pressure plasma, or CAP, are gaining increasing attention for their ability to inactivate bacteria and viruses^1â??3, and to oxidize numerous organic pollutants⁴ and specifically industrial dyes^5,6. CAP discharges in direct contact with an aqueous solution are known to produce a cocktail of reactive oxygen and nitrogen species in solution, including OH^â?¢ and O₂^â?¢-. The type and geometry of the discharge employed, the properties of the treated solution, all affect the quantity and ratio of species produced. These factors thus play an important role in optimizing such devices for both industrial and more specialized applications.

In this work, we first examine the factors affecting the generation and transport of highly reactive species produced by cold atmospheric plasma across the plasma-liquid interface. We present the results from studies on positive and negative polarity corona discharges in which the dye indigo carmine is used as a measure of oxidation. We comment on the origin of the reactive species produced (gas phase, boundary layer, or bulk solution) and the relative importance of kinetics versus convective and diffusive forces in optimizing the modification of a target.

References:
1. Traylor, M. J. et al. J. Phys. D. Appl. Phys. 44,(2011).
2. Pavlovich, M. J., Chang, H.-W., Sakiyama, Y., Clark, D. S. & Graves, D. B. J. Phys. D. Appl. Phys. 46,145202 (2013).
3. Aboubakr, H. a. et al. Appl. Environ. Microbiol. 81,3612â??3622 (2015).
4. Jiang, B. et al. Chem. Eng. J. 236,348â??368 (2014).
5. Brisset, J.-L., Benstaali, B., Moussa, D., Fanmoe, J. & Njoyim-Tamungang, E. Plasma Sources Sci. Technol. 20,034021 (2011).
6. Vautier, M. J. Catal. 201, 46â??59 (2001).