Development of ROS/RNS generation model in discharge electrolysis for new plasma application

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K14956
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: Muroran Institute of Technology
• Principal Investigator: Takahashi Kazuhiro 室蘭工業大学, 大学院工学研究科, 助教 (60746973)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 大気圧プラズマ / パルス放電 / プラズマ液体相互作用 / 可視化計測 / 活性酸素種 / シミュレーション

Outline of Final Research Achievements

A pulsed discharge is generated above a water surface, and the pH, temperature, and flow in water were visualized. The production rate of OH radicals is estimated using terephthalic acid as a chemical probe. It was found that H+ is generated in the water by the charge exchange reaction, and that toroidal temperature increase and flow occurs from the tip of the discharge. The flow velocity may be affected by the difference in the discharge propagation mechanism depending on the polarity and the Marangoni convection caused by the OH production. Furthermore, the by-products of terephthalic acid were identified and the conversion process of terephthalic acid based on those by-products was predicted. By solving the convection-diffusion equation in a one-dimensional model, the OH production rate was estimated to be 14 nmol/s.

Free Research Field

プラズマエレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

放電プラズマと水の相互作用として生じる，水中のpH，温度および流動を可視化し，そのメカニズムを考察した。また，より正確なOH生成レートの推定方法を導入し，水中に生成される短寿命種の生成レートの推定を可能とした。これらを液中化学反応に基づくROS/RNSの生成シミュレーションモデルに導入することで正確なROS/RNS生成特性のシミュレーションが可能となる。また，将来的に放電照射水の生成をコントロールし，プラズマ医療・農業分野への応用における放電照射水の低コスト化・高効率化の一助を担うための基礎的知見が得られたと考えらえる。