Molecular Dynamics Simulation of Thermal Decomposition of BTF/TNB

Explosive detonation is a high-speed and high-energy chemical-physical transformation process that rapidly generates high-temperature and high-pressure gases as well as shock waves. These energies are released intensely in a short time, exhibiting extremely strong destructive power. When these high-temperature and high-pressure gases and shock waves act on the surface of combustibles, they can instantly peel off the hot core on the surface, disrupting the conditions necessary for sustaining the combustion reaction and thereby achieving a fire-extinguishing effect. However, to attain this application goal, it is essential to select explosive materials with both high energy density and low sensitivity. In this study, DFTB-MD (Density Functional Tight-Binding Molecular Dynamics) and DFT (Density Functional Theory) methods were employed to systematically investigate the thermal decomposition process of benzotrifuroxan (BTF)/1,3,5-trinitrobenzene (TNB) cocrystal nanoparticles under high-temperature conditions. Our simulations reveal, for the first time, that the thermal decomposition mechanism of BTF/TNB cocrystal nanoparticles is strongly size-dependent: the 1.8 nm particles exhibit earlier ring-opening of BTF due to the higher surface-to-volume ratio, while the 2.2 nm particles show superior structural stability and lower molecular diffusivity. Meanwhile, increasing temperature from 2100 K to 2400 K shifts the dominant initial decomposition pathway from C–NO2 cleavage in TNB to ring rupture in BTF. These findings provide atomic-scale theoretical insights into the design and application of BTF/TNB cocrystal nanoparticles for explosion-based fire suppression.