Atomistic Insight into Thermal Decomposition of 1,3,5‐Triamino‐2,4,6‐trinitrobenzene Nanoparticles According to the ReaxFF Molecular Dynamics Method

Abstract

As a widely used wood explosive, 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and its nanoparticles are insensitive due to the graphene-like structure. In this paper, the decomposition processes of TATB and its nanospheres with different radius (30, 40, 50, 60, and 70 Å) at 2000 K and 3000 K are calculated by the reactive molecular dynamic simulations. The initial reactions and the evolution of clusters (whose molecular weight is larger than TATB) are analyzed. The results show that there are four major distinctive channels for the initial decomposition of 30 Å nano-TATB system: (1) the formation of HO fragment; (2) the C-NO 2 bond breaking to form NO 2 ; (3) conversion of nitro to nitroso; (4) hydrogen transfer. For the main production gases, the amount of CO 2 , N 2 and H 2 O will increase with the increase of temperature and the amount of H 2 O at 3000 K is obviously more than that at 2000 K accordingly to conventional TATB. This demonstrates that high temperature is beneficial to the pyrolysis of conventional TATB. In contrast to the results of TATB, the total amount of gas molecules of nanoparticles decreases, indicating that high temperature is not conducive to the pyrolysis reaction of nano-TATB. The results shed light on the complicated interplay between morphological evolution and external conditions. It provides insights into the thermal decomposition mechanism of TATB and its nanoparticles at the atomic level.

Molecular dynamic insight into octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and the nano-HMX decomposition mechanism

“…41 The original C/H/O/N ReaxFF has been used for several nitro explosives [41][42][43][44] and nanoparticles 45,46 and it correctly provided the 30-70 Å radius of nano-HMX, which was constructed from the original unit cell that was experimentally determined at room temperature. 47 The initial state of the system is shown in Fig. 1, which contains 64 molecules (S 0 , 1792 atoms, 30.28 × 23.89 × 23.65 Å3 ), and other systems are shown in Table 1 with three-dimensional periodic boundary conditions.…”