Production and loss of O2(1Δ g ) at atmospheric pressure using microwave-driven microplasmas
| Autor: | Alan R Hoskinson, Wilson T Rawlins, Kristin L Galbally-Kinney, Emily Gong, Jeffrey Hopwood |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Journal of Physics D: Applied Physics. 55:125208 |
| ISSN: | 1361-6463 0022-3727 |
| DOI: | 10.1088/1361-6463/ac4364 |
| Popis: | We have used arrays of microwave-generated microplasmas operating at atmospheric pressure to generate high concentrations of singlet molecular oxygen, O2(1Δ g ), which is of interest for biomedical applications. The discharge is sustained by a pair of microstrip-based microwave resonator arrays which force helium/oxygen gas mixtures through a narrow plasma channel. We have demonstrated the efficacy of both NO and less-hazardous N2O additives for suppression of ozone and associated enhancement of the O2(1Δ g ) yield. Quenching of O2(1Δ g ) by ozone is sufficiently suppressed such that quenching by ground state molecular oxygen becomes the dominant loss mechanism in the post-discharge outflow. We verified the absence of other significant gas-phase quenching mechanisms by measuring the O2(1Δ g ) decay along a quartz flow tube. These measurements indicated a first-order rate constant of (1.2 ± 0.3) × 10−24 m3 s−1, slightly slower than but consistent with prior measurements of singlet oxygen quenching on ground state oxygen. The discharge-initiated reaction mechanisms and data analysis are discussed in terms of a chemical kinetics model of the system. |
| Databáze: | OpenAIRE |
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