Flux of OH and O radicals onto a surface by an atmospheric-pressure helium plasma jet measured by laser-induced fluorescence
Flux of OH and O radicals onto a surface by an atmospheric-pressure helium plasma jet measured by laser-induced fluorescence
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DOI：
10.1088/0022-3727/47/12/125401
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发表时间：
2014-03
期刊：
影响因子：
--
通讯作者：
S. Yonemori;R. Ono
中科院分区：
文献类型：
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作者：
S. Yonemori;R. Ono
大气压氦等离子体射流作为一种用于癌症治疗、伤口愈合和消毒的尖端生物医学设备正引起人们的兴趣。羟基和氧自由基等活性氧物种被认为是影响生物等离子体应用的主要因素。在本研究中，利用激光诱导荧光测量了表面羟基和氧自由基的密度分布、时间行为和通量。用内径为4 mm的石英管，施加8千伏、10 kHz的脉冲高压，产生氦等离子体射流。为了评估皮肤表面状况与活性物质产生之间的关系，使用了三种表面：干燥、潮湿和大鼠皮肤。当氦气流量为1.5Min−1时，大鼠皮肤表面的OH密度径向分布在等离子体介导区中心处达到最大值1.2×1013 cm−3，O原子密度在距等离子体介导区中心2.0 mm处最大值为1.0×1015 cm−3。由于它们的寿命比脉冲间隔长，所以在放电脉冲的间隔期间，它们在等离子体射流流出物中的密度几乎是恒定的。它们的密度分布取决于氦气流量和表面湿度。根据这些结果，讨论了等离子体射流中产生OH和O的机理以及它们进入表面的通量。
The atmospheric-pressure helium plasma jet is of emerging interest as a cutting-edge biomedical device for cancer treatment, wound healing and sterilization. Reactive oxygen species such as OH and O radicals are considered to be major factors in the application of biological plasma. In this study, density distribution, temporal behaviour and flux of OH and O radicals on a surface are measured using laser-induced fluorescence. A helium plasma jet is generated by applying pulsed high voltage of 8 kV with 10 kHz using a quartz tube with an inner diameter of 4 mm. To evaluate the relation between the surface condition and active species production, three surfaces are used: dry, wet and rat skin. When the helium flow rate is 1.5 l min−1, radial distribution of OH density on the rat skin surface shows a maximum density of 1.2 × 1013 cm−3 at the centre of the plasma-mediated area, while O atom density shows a maximum of 1.0 × 1015 cm−3 at 2.0 mm radius from the centre of the plasma-mediated area. Their densities in the effluent of the plasma jet are almost constant during the intervals of the discharge pulses because their lifetimes are longer than the pulse interval. Their density distribution depends on the helium flow rate and the surface humidity. With these results, OH and O production mechanisms in the plasma jet and their flux onto the surface are discussed.