Probing the combustion characteristics of micron-sized aluminum particles enhanced with graphene fluoride

Graphene fluoride (GF) with its two-dimensional structure and high fluorine content on the surface can be used to enhance the combustion characteristics of micron-sized Aluminum (μAl) particles. However, the enhancing mechanisms of GF in Al combustion remain not fully understood. In this work, the effects of GF on combustion temperature, flame emission spectrum, ignition delay time, and condensed combustion products (CCPs) size of μAl were studied using laser ignition and optical diagnostic experiments. The combustion characteristics of GF- or polytetrafluoroethylene (PTFE)-modified μAl composite particles were compared to elucidate the ignition and combustion mechanism of different fluorides. The results show that the thermal decomposition behavior and the energy distribution among excited Al atoms differ significantly between GF and PTFE. Compared with PTFE, GF and its decomposition products have stronger excitation ability for high energy Al atoms, which is conducive to increasing the combustion temperature of particle flame. In addition, the ignition delay time and CCPs size of Al/GF are approximately 49∼66 % and 10 % less than those of Al/PTFE, respectively. These results provide a fundamental understanding and data support for the application of functionalized graphene in metal fuels and solid propellants.