Pore structure regulation of 3DOM CuBi2O4 based nanothermites for enhanced combustion and self-destruction

The Al/3DOM-CuBi 2 O 4 nanothermites with different contact extents were prepared using PMMA as a template. • 156 nm Al/3DOM-CuBi 2 O 4 has the best heat release and ignition characteristic. • DFT insights confirm strong electron transfer and adsorption capability in Al/CuBi 2 O 4 . • This thick microchip can be destroyed within a transient reaction for only 4 ms. Self-destructing microchips based on thermite reactions have emerged as an effective strategy for information security. However, conventional nanothermites suffer from unbalanced heat release, gas generation and pressure output, which severely restrict their destructive efficiency. Herein, we fabricated a three dimensionally ordered macroporous (3DOM) CuBi 2 O 4 /Al energetic composite via polymethyl methacrylate (PMMA) colloidal templating approach. Attributing to both the tunable pore sizes and distinct 3D structure of the CuBi 2 O 4 framework, the interfacial contact and diffusion length between fuel and oxidant can be effectively regulated. As a result, among the investigated samples, the system with a pore size of 156 nm exhibits the highest heat release of 1610.84 J/g, together with a peak pressure of 266 kPa and a pressurization rate of 1315 MPa/s. The optimized performance originates from an optimized balance between fuel-oxidizer interfacial contact and oxygen transport at an appropriate length scale, enabling efficient reaction propagation and enhanced reaction completeness. The 3DOM framework promotes uniform fuel distribution and efficient interfacial interactions, thereby facilitating rapid energy release. Density functional theory calculations further reveal enhanced electron transfer at the interface, supporting the accelerated reaction kinetics. More importantly, the fabricated energetic microchip can achieve complete physical self-destruction within 4 ms. The favorable combustion performance of Al/3DOM-CuBi 2 O 4 reveals the dependability of our proffered strategy for enhancing information security. Download: Download high-res image (208KB) Download: Download full-size image