Investigation of radical production and reaction mechanism for improvement of chemical reactivity using sub-atmospheric pressure plasma

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K14968
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Nakagawa Yusuke 東京都立大学, システムデザイン研究科, 助教 (80805391)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 中気圧プラズマ / ラジカル / レーザー分光

Outline of Final Research Achievements

Using a mid-pressure plasma, which is a plasma in 0.1-0.9 atm, we aimed to improve the radical flux and achieve uniform treatment while maintaining the diversity of the treatment target. The shape of the mid-pressure plasma was observed with an ICCD camera, and the behavior of atomic nitrogen as a reducing radical and atomic oxygen as an oxidizing radical was measured with laser spectroscopy in the mid-pressure plasma.
The results exhibited that a homogeneous plasma was formed when the pressure was reduced to 0.5 atm or lower. The fluxes of atomic nitrogen and atomic oxygen were 1.6 and 3.5 times higher at 0.3 atm than those at atmospheric pressure, respectively.

Free Research Field

放電プラズマ工学

Academic Significance and Societal Importance of the Research Achievements

大気圧プラズマを用いた化学反応は生体治療や液中粒子合成、大面積表面処理等に有効であるが、化学反応を司るラジカルの寿命が短いため、無効消費が多いという欠点がある。本研究では大気圧からわずかに減圧した中気圧プラズマを利用することで、ラジカルの生成量を大気圧と同程度以上に維持したまま、ラジカルの寿命を延長し無効消費を抑制できることを科学的に証明した。これにより大気圧プラズマで期待されている様々な適用分野において、プラズマ化学反応の効率が向上し実用化に大きく貢献できる。