O·, H·, and ·OH radical etching probability of polystyrene obtained for a radio frequency driven atmospheric pressure plasma jet
O·, H·, and ·OH radical etching probability of polystyrene obtained for a radio frequency driven atmospheric pressure plasma jet
复制标题
射频驱动大气压等离子体射流获得的聚苯乙烯的 O·、H·和·OH 自由基蚀刻概率
DOI：
10.1116/6.0000123
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
P. Bruggeman
中科院分区：
文献类型：
--
作者：
V. S. Kondeti;Yashuang Zheng;P. Luan;G. Oehrlein;P. Bruggeman
大气压等离子体射流在聚合物表面改性方面具有很大的潜力。在这项工作中，作者报告了射频驱动大气压等离子体射流对聚苯乙烯的蚀刻，重点研究了H⋅、O⋅和⋅OH自由基在这一过程中的作用。采用comsol多物理场反应流体动力学模型计算了到达聚合物表面的H⋅、O⋅和⋅OH自由基的绝对通量，该模型考虑了衬底附近边界层的详细输运现象。利用双光子吸收激光诱导荧光和激光诱导荧光实验验证了射流流出液中H⋅和⋅OH密度的模拟结果。聚苯乙烯表面的碳原子去除通量来自先前报道的使用相同等离子体源的测量。结果表明，衬底上方界面区域的边界层效应对计算的蚀刻概率有显著影响。反应概率（β）具有显著的不确定性，尽管β的2个数量级变化会导致测定的蚀刻概率的约1个数量级变化的不确定性。证实了聚苯乙烯被⋅OH自由基蚀刻的概率至少比聚苯乙烯被O⋅OH自由基蚀刻的概率大一个数量级。作者还证实了H⋅自由基对聚苯乙烯的弱蚀刻概率。该模型表明，30ppm o2杂质的存在可以导致Ar + 1% h2等离子体射流远端流出物中产生⋅OH自由基，其密度足以实现有效的蚀刻。
Atmospheric pressure plasma jets have great potential for the surface modification of polymers. In this work, the authors report on polystyrene etching by a radio frequency driven atmospheric pressure plasma jet with a focus on the role of H ⋅, O ⋅, and ⋅ OH radicals in this process. The absolute flux of H ⋅, O ⋅, and ⋅ OH radicals reaching the surface of the polymer was determined by a comsol multiphysics reacting fluid dynamics model incorporating detailed transport phenomena in the boundary layer near the substrate. The simulated results of H ⋅ and ⋅ OH densities in the jet effluent were experimentally verified by two-photon absorption laser induced fluorescence and laser induced fluorescence, respectively. The carbon atom removal flux from the polystyrene surface was taken from previously reported measurements using the same plasma source. The authors show that the boundary layer effects in the interfacial region above the substrate can have a significant impact on the calculated etching probabilities. The reaction probability ( β) has a significant uncertainty although a variation of 2 orders of magnitude in β leads to uncertainties of approximately 1 order of magnitude variation in the determined etching probability. The etching probability of polystyrene by ⋅ OH radicals was confirmed to be at least an order of magnitude larger than the polystyrene etching probability by O ⋅ radicals. The authors also confirmed the weak polystyrene etching probability by H ⋅ radicals. The model suggests that the presence of a 30 ppm O 2 impurity can lead to the production of ⋅ OH radicals in the far effluent of the Ar + 1 % H 2 plasma jet close to the substrate at sufficient densities to enable effective etching.