Spherical Micro-nano Encapsulated Boron-based Energetic Materials with Improved Combustion Performance

The low energy release efficiency seriously hinders the application of Boron (B) powder as metal fuel in solid propellants. To overcome this issue, a series of B-based micro-nanospheres were produced by encapsulating B-based metastable intermixed composites (MICs) with ammonium perchlorate (AP) through a solvent evaporation-induced self-assembly (EISA) method in this work. A self-developed combustion system that contains ignition pool, indicator light, and high-speed camera to precisely monitor ignition delay time and burning time was utilized. The EISA-prepared B/Bi2O3/AP composite show higher combustion temperature (1435 oC) and shorter ignition delay time (379±25 ms) than physically mixed sample (1264 oC and 1035±63 ms). The isolated reaction units of B/Bi2O3/AP-EISA micro-nano composite accelerate heat transfer and accumulation and reduce sintering and agglomeration, thus promoting the combustion efficiency of B powder. This study presents a promising strategy by doping and encapsulating process to increase the combustion performance of B based metal fuel.