Some metallic nanoparticles’ ignition temperature by thermodynamic consideration

Abstract

Self-propagating high-temperature synthesis (SHS) provides an attractive alternative route for the preparation of various compounds. Considering the diffusion reaction at the solid interface, the size-dependent activation energy and ignition temperature of the compounds synthesized by SHS can be used to help in modeling. Therefore, a quantitative model for size-dependent ignition temperature is established by considering energetic and physical characteristics. To the author’s knowledge, this is the first theoretical model to explore the effects of size on ignition temperature for SHS applications, with size ranging from nano- to microscale. An assumption of ideal SHS is made in the deduction of the model. As the size of reactants decreases, the ignition temperature decreases. This is because increasing the contact area and reducing the diffusion barrier between the reactants must be used specifically to calculate the reactants at the nanometer scale. The model predictions are still in good agreement with the experimental and theoretical observations for metallic aluminides and titanium carbide systems.