Atmosphere effects on 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) nanoparticle pyrolysis: A ReaxFF molecular dynamics study

1,3,5-Triamino-2,4,6-trinitrobenzene (TATB), an insensitive explosive, is exposed to the atmosphere during manufacture, storage and use, which can lead to changes in energy and sensitivity, particularly in nanoparticles. However, the underlying mechanisms of atmosphere effect on TATB pyrolysis remain poorly elucidated due to the limitations of experimental techniques in terms of temporal and spatial scales. This study employs molecular dynamics simulations to explore the impact of common atmospheres, including N₂ atmosphere, H₂O atmosphere, and NH₃ atmosphere, on the pyrolysis of TATB nanoparticles at the atomic level. The results demonstrate that all three atmospheres inhibit TATB pyrolysis, with N₂ atmosphere exhibiting the strongest inhibition, followed by NH₃ atmospheres, and H₂O atmosphere. Regarding the intrinsic mechanism, the inhibitory effects of different atmospheres can be classified into two categories: The influence of N₂ atmosphere and H₂O atmosphere is inert, as they hardly directly react with TATB but instead hinder the initial dehydrogenation reaction, thereby affecting the formation of key intermediates and final products; in contrast, NH₃ atmospheres not only inhibits these reactions but also tends to directly react with TATB to form larger molecules, which remain stable under thermal stimulation and suppress further decomposition of TATB.