Multifunctional 2D fluorinated coating and bioinspired interface on HMX for simultaneous desensitization and combustion enhancement

High sensitivity of energetic oxidizers and difficulties in activating passivated aluminum during the ignition are two serious obstacles for safe and efficient application of aluminized explosives. Herein, a safe and highly reactive HMX@PDA@FG (HPF) dual-shell oxidizer was constructed through functionalizing octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) core with a bio-enhanced interface polydopamine (PDA) and a two-dimensional (2D) fluorine source fluorinated graphene (FG) via bionic and self-assembly strategies. The synergistic integration of FG and PDA coatings achieves a remarkable reduction in HMX sensitivity (the impact energy increase from 7 to 28 J and friction load weight increase from 108 to 160 N). The 2D structure of FG notably enhances heat transfer within the system and leads to more rapid and concentrated decomposition of HMX. Furthermore, HPF oxidizers feature significant combustive activation effects for nano-aluminum due to high fluorine content of FG. Aluminized mixture HPF-10/n-Al exhibits superior combustion reactivity and energy output. The combustion heat of HPF-10/n-Al reaches 14,770.8 kJ/g, nearly 1000 kJ/g higher than HMX/n-Al, while the peak pressure and pressurization rate are approximately 1.5 and 4.9 times higher than HMX/n-Al. Hence, modifying multifunctional fluorinated graphene coating and bioinspired interface polydopamine on HMX shows great potential in enhancing both safety and energetic performance of aluminized explosives.