Efficient construction of core/double-shelled structured AP@nano-graphite@F energetic microcapsules with low sensitivity and hygroscopicity.

Ammonium perchlorate (AP) is widely utilized in aerospace, defense and other fields due to its high energy density, exceptional stability, easy availability and adaptability. However, the high sensitivity and hygroscopicity of AP severely constrain its application in numerous fields. In this study, a two-step continuous coating method was employed to construct AP-based energetic microcapsules with low sensitivity and hygroscopicity. The formation process of the F shell on the AP@nano-graphite surface was simulated using Materials Studio (MS), which proved the rationality of the shell formation process. In addition, the excellent electrical and thermal conductivity of the nano-graphite shell combined with the superior hydrophobicity and thermal insulation of the F shell advanced the high-temperature decomposition process of the AP-based energetic microcapsules, enhanced the hydrophobicity of the AP (the water contact angle increased from 0° to 73° and the hygroscopic rates decreased from 0.132% to 0.051%), and reduced the impact sensitivity of the AP (the value increased from 42.2 cm to 86.6 cm). Clearly, the diverse materials in the shell layer could endow the core AP with multiple functions. Therefore, this meaningful work provides a novel and extensive strategy to improve the performance of AP-based energetic microcapsules.