Preparation and Reactivity of Core-Shell Al@CL-20 Composites Embedded with Graphene-Based Complexes as Catalysts

Incomplete combustion of Al in solid propellants can be effectively resolved by coating of an oxidizer at the microscale. In this paper, Al@CL-20 composites with polydopamine as the interfacial layer were prepared using this strategy. The structure, heat of reaction, thermal decomposition properties, and combustion performances of these composites under the effects of graphene oxide (GO) and graphene-based carbohydrazide complexes (GO-CHZ-M, M = Co²⁺, Ni²⁺) have been comprehensively investigated. The experimental results show that the heat of reaction of Al@CL-20 is 6482 J g^-1, which is 561 J g^-1 higher than that of the corresponding mechanical mixture. The presence of GO-CHZ-Co can further increase the heat of reaction of Al@CL-20 to 6729 J g^-1 with a decreased activation energy by about 54.8%. Under the synergistic effect of interfacial control and GO-CHZ-M, the ignition delay time of Al@CL-20-Co decreases from 5.1 to 4.2 ms. Besides, the D₅₀ of the combustion condensed products (CCPs) decreased from 5.62 to 4.33 μm, indicating the combustion efficiency of Al is greatly improved.