Optimization of an Antisolvent Method for RDX Recrystallization: Influence on Particle Size and Internal Defects

The present study deals with the synthesis and characterization of pure RDX as well as ND-RDX (nanodiamond–hexahydro-1,3,5-trinitro-1,3,5-triazine) core–shell composites. RDX is one of the most widely used energetic materials. Variation of the experimental conditions of the antisolvent crystallization process leads to micrometer-sized RDX particles with tailored size and morphology. Tuning the cooling rate has a particular influence on the crystal growth rate and, as a consequence, on the formation of internal crystal defects in the form of fluid inclusion. The sensitivity of RDX toward mechanical stress is shown to be dependent on crystal shape (isotropy/anisotropy) and presence of inclusions. Introduction of NDs in the antisolvent process influences the reaction conditions in such a way that nanosized composite particles are formed. In the nanostructured final material NDs play the role of a core homogeneously coated by a thin layer of RDX. The fact that NDs act as seeds for RDX crystallization and core–shell growth during the antisolvent process is a result of great novelty. Nanostructured energetic materials with improved sensitivity properties can be obtained this way.