Achieving superior ignition and combustion performance of Al/I2O5 biocidal nanoenergetic materials by CuO addition

Abstract

It was found that all iodine-containing biocidal energetic materials has a relatively long ignition delay upon combustion. A shorter ignition time (from the thermal trigger to the peak pressure) for Al/iodine oxides might further boost their combustion performance due to their high reactivity and high gas release rate. To achieve this goal, a secondary oxidizer, CuO, is incorporated into Al/I2O5 at different mass content keeping the overall thermite stoichiometry constant. The ternary Al/I2O5/CuO thermites were characterized in ignition using a T-jump ignition temperature set up, and in combustion in a constant volume combustion cell. Consequently, all ternary thermites outperform traditional Al/I2O5 counterpart with an optimum for 80/20 wt% of I2O5/CuO. This later composition ignites in 0.01 ms (30 times shorter than Al/I2O5) and produces peak pressure and pressurization rate of ∼4 and 26 times greater than those produced by Al/I2O5. A series of additional characterizations using Fourier-transform infrared spectroscopy, Differential Scanning Calorimetry, Electrical/Thermal conductivity measurement, etc., permitted to unravel the cause of such improvement and to propose a reaction mechanism for this ternary Al/I2O5/CuO system. From an applications point of view, this study proposes a facile, inexpensive and efficient way to enhance the combustion performance of Al/I2O5 biocidal nanoenergetic materials.