Complexity visualization and numerical simulation of reacting chemistry in plasma-treated liquid

Low-temperature plasmas have been widely studied in the fields of biomedicine, agriculture, sustainable energy conversion. In these applications, plasma-treated water is gaining increasing attention because they can produce abundant reactive species, whereas the aqueous chemistry is complex and its mechanism is not fully understood. We still have some challenges to reach comprehensive understanding of the nature of plasma-treated liquid chemistry. This study proposes mathematical/numerical approaches to tackle the issue. The complex network analysis based on the graph-theory, one of the information mathematics, enable us to reveal the hidden feature of liquid chemistry through the visualization and centrality-based identification of the reacting network [1,2]. A newly-developed one-dimensional reaction-diffusion model with hundreds of reaction processes of air-saturated water can simulate the influence of the irradiation of plasma-induced reactive species on the liquid chemistry by quantifying how various plasma species permeate into the liquid and what reactions are triggered.[1] T. Murakami and O. Sakai, Plasma Sources Sci. Technol. 29 (2020) 115018 [2] O. Sakai, S. Kawaguchi and T. Murakami, Jpn. J. Appl. Phys. 61 (2022) 070101