Gas-Phase Synthesis of Perfluoroalkyl-Functionalized Graphene and Its Desensitization Effect on 1,3,5,7-Tetranitro-1,3,5,7-Tetraazacyclooctane

Energetic materials, such as 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), are known for their high energy output but low safety. The application of fluorine-containing materials in energetic materials can yield extraordinary results. This paper presents a gas-phase synthetic method for preparing perfluoroalkyl-functionalized graphene (PFG) and examines its desensitizing effect on HMX. PFG was synthesized under mild and safe conditions, and its structure was characterized. For comparison, alkyl-functionalized graphene (RG) was prepared using the same method. Seven composites of HMX with varying fluorine contents of PFG, as well as graphene, graphene oxide, amino-functionalized graphene, and RG were prepared by a solvent/nonsolvent method. HMX crystals grow as ellipsoids without sharp angles in PFG dispersions, which facilitate the reduction of mechanical sensitivity. Thermal analyses were conducted to determine the apparent activation energy and physical model of the thermal decomposition process. The results show that PFG inhibits the decomposition of HMX at low temperatures but accelerates its rapid decomposition rate at high temperatures. Mechanical sensitivity and thermal analysis studies suggest that 15%PFG is a promising coating agent to improve the safety of energetic materials.