Agarwal Prawal P K, Jensen Devon, Chen Chien-Hua, Rioux Robert M, Matsoukas Themis
Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Advanced Cooling Technologies, Inc., Lancaster, Pennsylvania 17601, United States.
ACS Appl Mater Interfaces. 2021 Feb 10;13(5):6844-6853. doi: 10.1021/acsami.0c20825. Epub 2021 Jan 29.
The development of an in situ nonthermal plasma technology improved the oxidation and energy release of boron nanoparticles. We reduced the native oxide layer on the surface of boron nanoparticles (70 nm) by treatment in a nonthermal hydrogen plasma, followed by the formation of a passivation barrier by argon plasma-enhanced chemical vapor deposition (PECVD) using perfluorodecalin (CF). Both processes occur near room temperature, thus avoiding aggregation and sintering of the nanoparticles. High-resolution transmission electron microscopy (HRTEM), high-angular annular dark-field imaging (HAADF)-scanning TEM (STEM)-energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) demonstrated a significant reduction in surface oxide concentration due to hydrogen plasma treatment and the formation of a 2.5 nm thick passivation coating on the surface due to PECVD treatment. These results correlated with the thermal analysis results, which demonstrated a 19% increase in energy release and an increase in metallic boron content after 120 min of hydrogen plasma treatment and 15 min of PECVD of perfluorodecalin. The PECVD coating provided excellent passivation against air and humidity for 60 days. We conclude in situ nonthermal plasma reduction and passivation lead to the amelioration of energy release characteristics and the storage life of boron nanoparticles, benefits conducive for nanoenergetic applications.
一种原位非热等离子体技术的发展改善了硼纳米颗粒的氧化和能量释放。我们通过在非热氢等离子体中处理来减少硼纳米颗粒（70纳米）表面的原生氧化层，随后使用全氟萘烷（CF）通过氩等离子体增强化学气相沉积（PECVD）形成钝化屏障。这两个过程都在接近室温的条件下发生，从而避免了纳米颗粒的聚集和烧结。高分辨率透射电子显微镜（HRTEM）、高角度环形暗场成像（HAADF）-扫描透射电子显微镜（STEM）-能量色散光谱（EDS）以及X射线光电子能谱（XPS）表明，氢等离子体处理使表面氧化物浓度显著降低，并且PECVD处理在表面形成了2.5纳米厚的钝化涂层。这些结果与热分析结果相关，热分析结果表明，经过120分钟的氢等离子体处理和15分钟的全氟萘烷PECVD处理后，能量释放增加了19%，金属硼含量也有所增加。PECVD涂层在60天内提供了优异的抗空气和防潮钝化性能。我们得出结论，原位非热等离子体还原和钝化导致硼纳米颗粒的能量释放特性和储存寿命得到改善，这有利于纳米含能材料的应用。
