Ignition and Combustion Characteristics of Nanoaluminum with Copper Oxide Nanoparticles of Differing Oxidation State
详细信息 查看全文
- 作者：Garth C. Egan ; Kyle T. Sullivan ; Tammy Y. Olson ; T. Yong-Jin Han ; Marcus A. Worsley ; Michael R. Zachariah
- 刊名：Journal of Physical Chemistry C
- 出版年：2016
- 出版时间：December 29, 2016
- 年：2016
- 卷：120
- 期：51
- 页码：29023-29029
- 全文大小：363K
- ISSN：1932-7455
文摘
The importance of the oxidation state of an oxidizer and its impact on gaseous oxygen and total gas production in nanocomposite thermite combustion was investigated by probing the reaction and ignition properties of aluminum nanoparticles (Al-NPs) with both cupric oxide (CuO) and cuprous oxide (Cu2O) nanoparticles. The gas release and ignition behavior of these materials were tested with >105 K/s temperature jump (T-jump) heating pulses in a high temporal resolution time-of-flight mass spectrometer (ToF-MS) as well as in an argon environment. Reactivity was tested using a constant volume combustion cell with simultaneous pressure and optical measurements. A variety of Cu2O particle sizes ranging from 200 to 1500 nm were synthesized and found to release oxygen at ∼1200 K, which is higher than the values found for a variety of CuO particle sizes (∼1000 K). Both oxides were found to ignite around 1000 K, which implies a consistent ignition mechanism for both through a condensed phase pathway. The higher oxidation state (CuO) thermites were found to react faster and produce higher pressures by several orders of magnitude, which implies that gaseous species play a critical role in the combustion process. Differences in reactivity between argon and vacuum environments and the use of Cu diluent to simulate Cu2O suggest that it is the intermediate product gas, O2, that plays the most significant role in combustion as an enabler of heat transfer and a secondary oxidizer. The lack of any oxidizer size dependence on ignition is suggestive of rapid sintering that wipes out the effect of enhanced interfacial contact area for smaller oxidizers.