A Review of Nano-Structured Thermites and Explosives: Synthesis and Emerging Applications

Lead-based primary explosives are highly common in the military, mining and pyrotechnics. However, lead is non-biodegradable and poses a serious threat to the environment and living beings. Lead is a potent neurotoxin that causes organ damage and affects cognitive development in humans. It contaminates the air, water and soil, thereby affecting the flora and fauna through bioaccumulation and food chain contamination. It is also notorious for degrading soil fertility and biodiversity. The search for a greener alternative landed on nanostructured materials, fuelling considerable research in this domain. Although their large-scale manufacturing is challenging, these materials promise enhanced performance, safety and reliability over existing systems. The SFE method has been identified as a major breakthrough in facilitating mass-scale manufacturing of such explosive nanoparticles with decent productivity. Coating these nanoparticles with nanothermites resulted in a benign alternative with improved performance over traditional lead-based explosives, called NSTEX. This eliminates the risk of lead contamination while also improving the explosive performance. Despite the success of this system, stabilising these mixtures into operational systems has remained a challenge, hindering its application. A breakthrough in this aspect could be a significant step forward in greener and safer pyrotechnics for the future.