A comprehensive review of two currently used improvised explosives, tetraammine copper nitrate (TACN) and perchlorate (TACP), is presented. The review focuses on the physical and chemical properties, thermal decomposition, sensitivity, and detonation parameters. Historical uses of TACN, as well as recently proposed uses of both complexes, are mentioned. The undesired formation of TACN when copper or its alloys come into contact with ammonium nitrate is also discussed.

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This study investigates the effect of ambient pressure on ignition delay for B/KNO₃ using laser ignition. Experiments were conducted in air with ambient pressure as a parameter, and the influence of the generated gas was examined by comparing vertical and horizontal laser irradiation. The results showed that in vertical irradiation, ignition delay increases as ambient pressure rises. This is because the generated gas interferes with the laser, and the gas density increases with pressure, reducing laser intensity and heat transfer to the ignition charge. At lower pressures, gas density decreases due to diffusion, leading to less laser attenuation and shorter ignition delays. In horizontal irradiation, the range of the ignition delay range with respect to the ambient pressure is much smaller than that of vertical irradiation. The generated gas moves upward due to buoyancy, reducing interference between the gas and the laser. These findings indicate that ambient pressure significantly affects ignition delay by influencing gas generation and laser attenuation.

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Hybrid rockets are gaining attention as a safe and cost-effective alternative to conventional chemical rockets. However, a key challenge remains: their low fuel regression rate. To address this shortcoming, microcrystalline wax (WAX), a petroleum-derived solid fuel, has been explored. Although it is effective, its use raises environmental concerns. This study was conducted to enhance sustainability by incorporating cornstarch, a renewable biomass product, into WAX.
The study builds on earlier theoretical calculations and ignition experiments, along with combustion experiments and thermal analysis using a differential scanning calorimeter (DSC). Combustion experiments evaluated the fuel regression rate and characteristic velocity, revealing no marked performance degradation with increasing cornstarch content. Moreover, DSC analysis revealed that the onset temperature increased with higher cornstarch ratios, whereas the total calorific value was lowest at 20 mass% and peaked at 100 mass%.
These findings suggest that cornstarch-added WAX solid fuel can serve as a viable and environmentally friendly alternative for hybrid rockets, offering comparable performance to WAX while reducing reliance on petroleum-derived resources.

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Theoretical design of molecular hybrids of 2-(dinitromethylene)-1,3-diazacyclopentane (DNDZ) (a derivative of FOX-7) was done by linking the DNDZ to known energetic materials via a -CH₂- chain. A total of 12 novel molecular hybrids of DNDZ were designed, and their performance parameters were studied computationally. All the calculations for the molecules were done successfully to obtain these properties, which were further compared with DNDZ and RDX. Molecule 1, a hybrid of DNDZ and 2,3,4,5-tetranitro-1H-pyrrole, performed way better than the rest of the molecules and even better than DNDZ and RDX. As much as this molecule has the best detonation parameter, it is very sensitive to impact with the calculated impact sensitivity (IS) of 6 J. Molecule 12 has detonation performance better than all the molecules except molecule 1, and it has a good balance between detonation performance and impact sensitivity as compared to molecule 1.

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Controlling rock fragmentation and ground vibration is essential in rock blasting to ensure resource uniformity and mitigate environmental impacts. The air-deck blasting method, which incorporates an air gap into the blasthole, has been widely employed to address these challenges. Building on prior research, we developed a modified air-deck charging technique utilizing a paraffin-waxed paper tube to create a stable air gap, demonstrating reductions in vibration levels and enhanced fragment uniformity. Despite its practical advantages, the mechanisms underlying this method remain partially understood. To investigate these mechanisms, we applied three-dimensional combined finite-discrete element method (3-DFDEM) simulations, analyzing mainly rock fragmentation, and ground vibration patterns. The comparative results between conventional and air-deck blasting provide valuable insights into the method’s performance and potential applications.

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Underwater shock waves generated by explosives provide superior processing range and precision due to their high energy density, outperforming other shock-wave-based material processing methods. However, practical applications require minimizing explosive usage for safety and efficiency. Detonators contain the smallest amount of explosive for practical use. A major challenge in underwater detonator explosions is the rapid pressure attenuation caused by the threedimensional expansion of shock wave energy. To mitigate this, shock wave reflections from walls can be utilized to control propagation direction and reduce pressure attenuation, thereby improving processing efficiency. Depending on the wall geometry, the shock wave front can be flattened while maintaining high pressure, ensuring uniform force application and enhancing processing quality. This study developed a numerical model using Ansys Autodyn to simulate underwater detonator explosions. The propagation of shock waves captured through high-speed imaging and the measured pressure closely matched the simulation results, validating the model’s accuracy. These findings provide a foundation for optimizing reflective wall designs, contributing to enhanced material processing techniques and improved shock wave convergence applications.

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