Preparation, ignition and combustion of reactive metal-sulfur nanocomposites

Mechanical milling is applied to synthesize reactive metal-sulfur nanocomposites. Specifically, magnesium-sulfur, aluminum-sulfur and zirconium-sulfur nanocomposite powders are prepared. Each powder particle contained homogeneously mixed sulfur and respective metal. These materials are expected to be stable in room air. They are also expected to release sulfur upon ignition; the released sulfur may serve as a biocidal agent. The ignition temperatures of the three prepared sulfur-bearing materials fall in a range of 750 - 1000 K. All prepared materials are successfully ignited in electrostatic discharge experiment as well as in a constant volume explosion experiment. The most sensitive material to spark ignition is magnesium-sulfur composite. In aerosolized combustion experiment, magnesium-sulfur exhibits the highest burning efficiency and highest rate of pressure rise. Materials with larger particle sizes appear to have longer ignition delays. Shorter burn times measured in the electrostatic discharge ignition test correlate with the greater rates of pressure rise obtained in the constant volume explosion test