Controlled microdroplet transport in an atmospheric pressure microplasma
Controlled microdroplet transport in an atmospheric pressure microplasma
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DOI：
10.1063/1.4922034
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发表时间：
2015-03
影响因子：
4
通讯作者：
P. Maguire;C. Mahony;Colin Kelsey;A. Bingham;E. Montgomery;Euan Bennet;Hugh Potts;D. Rutherford-D.-Ru
中科院分区：
文献类型：
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作者：
P. Maguire;C. Mahony;Colin Kelsey;A. Bingham;E. Montgomery;Euan Bennet;Hugh Potts;D. Rutherford-D.-Ru
本文报道了大气压下近孤立微米级液滴向低温He-Ne稳态射频等离子体的受控注入。H2O液滴流被限制在2 mm直径的石英管内。试管出口处的成像表明对数正态液滴尺寸分布，初始计数平均直径为15 μm，暴露于等离子体后降至13 μm。径向速度分布近似抛物线，表明接近层流条件，大部分液滴以>75%的局部气体速度行进，等离子体渡越时间<100 μs。最高气体温度，确定从氮谱线，低于400 K和所观察到的液滴尺寸减小意味着额外的因素超出标准蒸发，包括电荷和表面化学效应。受控微滴流的演示为气相微反应器和等离子体医学活性物质的远程递送开辟了可能性。
We report the controlled injection of near-isolated micron-sized liquid droplets into a low temperature He-Ne steady-state rf plasma at atmospheric pressure. The H2O droplet stream is constrained within a 2 mm diameter quartz tube. Imaging at the tube exit indicates a log-normal droplet size distribution with an initial count mean diameter of 15 μm falling to 13 μm with plasma exposure. The radial velocity profile is approximately parabolic indicating near laminar flow conditions with the majority of droplets travelling at >75% of the local gas speed and having a plasma transit time of <100 μs. The maximum gas temperature, determined from nitrogen spectral lines, was below 400 K and the observed droplet size reduction implies additional factors beyond standard evaporation, including charge and surface chemistry effects. The demonstration of controlled microdroplet streams opens up possibilities for gas-phase microreactors and remote delivery of active species for plasma medicine.