Assembly and reactive properties of Al/CuO based nanothermite microparticles
Assembly and reactive properties of Al/CuO based nanothermite microparticles
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DOI：
10.1016/j.combustflame.2014.02.003
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发表时间：
2014-08-01
影响因子：
4.4
通讯作者：
Zachariah, Michael R.
中科院分区：
文献类型：
--
作者：
Wang, Haiyang;Jian, Guoqiang;Zachariah, Michael R.
人们普遍认为，纳米铝热剂高反应性的关键参数是燃料和氧化剂之间的紧密界面接触。人们已采用各种方法将燃料和氧化剂紧密结合在一起，包括溅射沉积[1]和阻滞研磨方法[2]。在本文中，我们展示了一种电喷雾路线，用少量的高能粘合剂将 Al 和 CuO 纳米粒子组装成微米复合材料，该复合材料表现出比传统物理混合制成的纳米铝热剂更高的反应性。电喷雾方法能够产生具有窄尺寸分布的微米级颗粒，其内表面积大致相当于纳米颗粒的比表面积。通过改变用作粘合剂的硝化纤维含量，可以轻松调节微米级复合材料的尺寸。复合材料在密闭压力室中燃烧，并在细的快速加热的金属丝上燃烧，以观察燃烧行为。 5 wt.% 硝化纤维样品显示出相对于物理混合情况的最佳响应，压力和加压速率高出 3 倍。这些微米颗粒的点火特性基本上与纳米铝热剂相同，尽管它们的物理尺寸要大得多。电喷雾组装工艺似乎具有潜在的优势。 1、加强燃料与氧化剂的混合； 2. 硝化纤维内部释放气体，迅速分离颗粒，防止烧结。后一点是通过比较燃烧后的产物粒度分布来显示的。由爱思唯尔公司代表燃烧研究所出版。
It is generally agreed that a key parameter to high reactivity in nanothermites is intimate interfacial contact between fuel and oxidizer. Various approaches have been employed to combine fuel and oxidizer together in close proximity, including sputter deposition [1], and arrested milling methods [2]. In this paper, we demonstrate an electrospray route to assemble Al and CuO nanoparticles into micron composites with a small percentage of energetic binder, which shows higher reactivity than nanothermite made by conventional physical mixing. The electrospray approach offers the ability to generate microscale particles with a narrow size distribution, which incorporates an internal surface area roughly equivalent to the specific surface area of a nanoparticle. The size of the micron scale composites could be easily tuned by changing the nitrocellulose content which is used as the binder. The composites were burned in a confined pressure cell, and on a thin rapidly heated wire to observe burning behavior. The sample of 5 wt.% nitrocellulose showed the best response relative to the physical mixing case, with a 3x higher pressure and pressurization rate. The ignition characteristics for these micron particles are essentially equivalent to the nanothermite despite their significantly larger physical size. It appears that electrospray assembly process offers to potential advantages. 1. Enhanced mixing between fuel and oxidizer; 2. Internal gas release from nitrocellulose that separates the particles rapidly to prevent sintering. The later point was shown by comparing the product particle size distribution after combustion. Published by Elsevier Inc. on behalf of The Combustion Institute.