Self-assembly of composite salts induced uniform, ammonium perchlorate-catalytic, ignitable and energetic coating on aluminum fuels

Ammonium perchlorate (AP) is an important oxidant of solid propellant, and its decomposition is of great significance for improving combustion properties of solid propellants. However, it is difficult to balance AP-catalytic effect, ignition and energy level. In this study, lithium hexafluorophosphate (LiPF₆), ferric chloride (FeCl₃) and 1,2,4-triazole were self-assembled on aluminum particles via ionic bonding and metallic coordination. It highly catalyzed the thermal decomposition of AP, which reduced the decomposition temperature of AP by 29.4 °C. The thermal oxidation reactivity of coated-aluminum was much higher than that of raw aluminum powder, and its exothermic enthalpy was 3.45 times that of raw aluminum. The combustion heat was also improved. After ignition delay of 0.2 s, Al/CM-4 was burnt violently at 740 °C, while raw Al could not be ignited even at 950 °C. Our work provides an effective strategy for high-performance self-assembly coating on Al fuels, which addressed big significance in AP-containing propellants and explosives. Besides, such organic/inorganic composite self-assembly system may also be instructive for future design of heterogeneous surface, multifunctional coating, protective interface, and etc.