This DTRA (Defense Threat Reduction Agency) project develops a combination of reactive materials and biocidal compounds for the purpose of bioagent defeat. The reactive material is nano-layered metallic particles that reach very high temperatures when reacted and produce a significant amount of heat in the process. This heat is used to decompose an iodine-containing compound, resulting in a release of iodine gas, which is a known biocide.
The goal of the DTRA project is to use a combination of reactive materials and biocidal compounds to destroy bioagents such as anthrax. The reactive materials are composed of many layers of different metals, where each layer is on the order of just a few hundred atoms thick. When a small amount of energy is supplied to the material, these layers can mix and release large amounts of heat in the process described in Figure 1(a).
Part of this project involves fabricating these materials as small particles so that they can be mixed with an iodine compound in powder form. Upon ignition, the reactive metal particles will supply heat that will burn spores in the vicinity, as well as decompose the solid iodine compound to form iodine gas. This gas is released in a dramatic, deep purple cloud that has biocidal properties and will chemically destroy the dangerous spores.
The reactive particles are primarily being used as a heat source to decompose the iodine compounds, and so one goal is to maximize their heat generation. This is quantified using a specialized bomb calorimeter which the schematic drawing is in Figure 1(b).
Below is a slow motion video of reactive particles mixing with HIO3, which decomposes into biocidal iodine gas.