Size effect on the pyrolysis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) nanoparticles: a ReaxFF molecular dynamics study

Abstract

The nanoscale form of the typical insensitive energetic material 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) exhibits the capability to improve the energy performances while maintaining low sensitivity compared to raw TATB. Investigating the particle size effect on the intrinsic pyrolysis mechanisms facilitates the selection of the TATB particle size in applications to ensure efficient energy release and high safety levels. However, the intrinsic mechanism of this effect remains unclear. This study focuses on pyrolysis as a prerequisite behavior for energy release, employing reactive molecular dynamics simulations to investigate the pyrolysis of TATB nanoparticles with different sizes, aiming to explore the qualitative changes in thermal properties at the atomic level. Results demonstrate that with increasing particle size, the decomposition rate of TATB decreases. Smaller particles exhibit a propensity towards dehydrogenation and C–NO₂ bond cleavage reactions. However, larger nano-TATB particles demonstrate a preference for dimerization, which results in the formation of clusters with greater polymerization and increased stability. The highly polymerized clusters are stable under thermal stimulation, inhibiting further decomposition of TATB. These insights reveal the mechanism underlying the qualitative change in the energy performance of TATB nanoparticles at the atomic level.