Simplified quantitative analysis method and its application in the in-situ synthesized copper-based azide chips

Copper-based azide (Cu(N₃)₂ or CuN₃, CA) chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years. However, the advantages of in-situ synthesis method, including small size and low dosage, bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips. The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability. In this work, Cu(N₃)₂ and CuN₃ components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N₃⁻ concentration through spectrophotometry. The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied, ensuring the accuracy and reproducibility of test results. The optimized method is linear in range from 1.0–25.0 mg/L, with a correlation coefficient R² = 0.9998, which meets the requirements of CA chips with a milligram-level content test. Compared with the existing ICP method, component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy. Moreover, as its application in miniaturized explosive systems, the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied. This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.