(388n) Thermite Reaction Based On Nano-Al and Iodine Pentoxide: Ignition and Combustion Characterization

Thermite reactions with high energy release and biocidal agent production are of interest for their potential applications in bio-agent defeat. In this study, ignition and combustion behavior of nano-Al and iodine pentoxide were investigated. Cyro-milling was used to produce fine particles, but found only to be effective for preparation of micro-sized iodine pentoxide. The ignition and reaction of the prepared nano-Al/micro-I₂O₅ thermite samples were systematically studied by a rapid wire heating technique using a temperature-jump/time-of-flight mass spectrometer and a high speed digital camera. Time-resolved mass spectra results showed that nano-Al/micro-I₂O₅ reactions can produce a lot of iodine species which were suggested to be good biocidal agents. The ignition temperature of nano-Al/micro-I₂O₅ thermite in air at atmospheric pressure was found to be ~810 K, lower than ignition temperature ~940 K in vacuum. Constant-volume pressure cell tests were run to characterize the pressure and optical signals during the combustion, and the performance of the iodine containing thermites was compared with other thermite systems. The results show that Al/I₂O₅ thermite composite outperform the traditional Al/CuO and Al/Fe₂O₃ thermite systems in terms of peak pressure, pressurization rate and burning time. Transmission electron microscope with X-ray compositional microanalysis characterization were performed to analyze the post-combustion products and showed that the production of iodine species and aluminum oxides. Our study of nano-Al and iodine pentoxide reactions shows that these iodine containing thermite reactions are very reactive and suggested to effectively produce iodine gas which can be used in microbial agent defeat applications.