Dispersion of nanocatalytic materials: a new strategy to explore the best catalytic performance for the thermal decomposition of multiple size ammonium perchlorate

Currently, it is widely recognized by scholars that nanocatalytic materials with high dispersity have a better catalytic effect on the thermal decomposition of energetic materials. However, there are significant challenges in exploring the relationship between the dispersity and catalytic performance of NCMs in NCMs/EMs, and with the literature rarely reported. In this study, we established a quantitative calculation method for the dispersity index of NCMs in NCMs/EMs composites based on the differential UV absorption between NCMs and EMs. Subsequently, we prepared CuCr₂O₄ (CCO)/raw ammonium perchlorate (AP) and CCO/fine AP composite with different dispersity using mechanical mixing and ultrasonic mixing techniques. Their formation was confirmed through X-ray diffraction (XRD), scanning electron microscopy (SEM) and particle size analysis. Solid UV tests demonstrated the highest repeatability of the UV absorption peaks near the wavelength of 212 nm. By measuring the absorbance at 212 nm for different nano-CCO/AP composite, the solid UV values were obtained. The dispersity index for different samples was calculated using the dispersity calculation method. Furthermore, differential scanning calorimetry (DSC) tests were conducted on nano-CCO/AP composite samples with different dispersity. The results indicated that the higher the dispersity index of nano-CCO, the better promotion of thermal decomposition on AP (more advance in high-temperature decomposition peak). Finally, the application of nano-CCO/AP composites with different dispersity in solid propellants verified the positive correlation between the dispersity of NCMs and their catalytic performance. This study lays the foundation for establishing a new strategy to evaluate the dispersity of NCMs and is expected to lead the trend of the application of NCMs in the field of EMs.