Colloidal Nanothermite Particles: Advanced Nanocatalyst and Energy Dense Material for Ammonium Perchlorates

While ferric oxide is frequently used as a catalyst, aluminum, with combustion enthalpy 32000 J g −1 , is a versatile highly energy-dense material. This binary mixture can achieve a synergistic impact with a strong thermite reaction. Additionally, nanoscale particles can offer better interfacial surface area, catalytic effect, and a high heat release rate. This study reports on the facile fabrication of colloidal ferric oxide nanoparticles (Fe 2 O 3 NPs) of 5-nm average size; aluminum nanoplates of 100 nm were employed. Colloidal nanothermites (Fe 2 O 3 /Al) were synthesized and integrated into ammonium perchlorate (APC) via co-precipitation. Uniform dispersion of nanothermite particles into APC was confirmed via elemental mapping using an EDAX detector. The nanothermite mixture's potentials (as a catalyst and highly energy-dense material) was described by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Thermite NPs offered a decrease in APC endothermic phase change by 48%, increasing the total heat released by 68%. While APC demonstrated a decomposition enthalpy of 836 J/g, for the APC nanocomposite it was 1405 J/g. Aluminum particles increased decomposition enthalpy, and Fe 2 O 3 NPs acted as an effective catalyst to decrease the required activation energy. The kinetic decomposition study of APC nanocomposite was investigated via isothermal heating using TGA. Nanothermite particles offered a reduction in APC activation energy by 11% and 14% using Kissinger's and Kissinger–Akahira–Sunose (KAS) models, respectively. Herein, this is the first report on catalytic activity assessment of colloidal nanothermite particles on APC decomposition. Graphic Abstract