Silver ferrite: a superior oxidizer for thermite-driven biocidal nanoenergetic materials

Silver-containing oxidizers are of interest as biocidal components in energetic application such as thermites due to their biocidal agent delivery. In this study, AgFeO(2), was evaluated as an oxidizer in aluminum-based thermite system. This novel oxidizer AgFeO(2) particles were prepared via a wet-chemistry method and its structure, morphologies and thermal behavior were investigated using X-ray diffraction, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry, and time-resolved temperature-jump time-of-flight mass spectrometry. The results indicate the decomposition pathways of AgFeO(2) vary with heating rates from a two-step at low heating rate to a single step at high heating rate. Ignition of Al/AgFeO(2) occurs at a temperature just above the oxygen release temperature that is very similar to Al/Fe(2)O(3) and Al/CuO. However, with a pressurization rate three times of Al/CuO, Al/AgFeO(2) yields a comparable result as to Al/hollow-CuO or Al/KClO(4)/CuO, with a simpler preparation method. The post combustion products demonstrated that the Al/AgFeO(2) thermite reaction produces a fine dispersion of elemental nanosized silver particles which coats the larger alumina particles and is thus bioavailable.