Investigation of core/shell nanoparticles properties by classical molecular dynamic study

The synthesis of hexolite by Spray Flash Evaporation (SFE) recently led to the formation of new core/shell highly energetical nanoparticles [1]. The detonation of such compounds produce very small nanodiamonds of high interest for electronics and biomedical applications. It was revealed that such production is influenced by the core/shell ratio, their size and interfaces features (significant at nanometric level). To manage these factors, the determination of the core/shell thermophysical properties and the underlying mecanisms leading to their formation is crucial.

Due to the thermal instability of hexolite core/shell structures, experimental characterization of these systems is challenging therefore a theoretical investigation appeared as a relevant approach to elucidate the properties of these heteregenous materials under ambiant and extreme conditions.

This task is undertaken by molecular dynamic simulation, performed using the STAMP code developed at CEA/DAM [2].

In this work, we present a molecular dynamics study of the thermophysical properties of model core-shell RDX/TNT nanoparticles. We focus on the nature of the core-shell interface with comparison to regular planar interfaces. The SFE process is also tentatively simulated in order to unravel the first mechanisms involved in the formation of this peculiar structures.