Reaction mechanism and sensitivity enhancement of energetic materials doped with carbon nanotubes under electric fields by molecular dynamics simulations†

Energetic materials (EM) can be remotely, uniformly and rapidly excited by electromagnetic radiation. Mastering the response mechanism of EM to electromagnetic radiation and promoting the efficient utilization of electromagnetic energy are fundamental to the development of electromagnetic radiation-induced explosive technologies. EM are generally non-magnetic, so the effect of magnetic fields in the system can usually be negligible; instead, the focus is on the interaction between electric fields and EM. In this paper, ReaxFF-lg reactive molecular dynamics simulations were performed to investigate the reaction process of pure RDX systems and RDX systems doped with single-walled carbon nanotubes (SWCNTs) under different electric fields and temperatures, and the response mechanisms of the two systems under electric fields were obtained. A method for estimating the field enhancement factor of SWCNTs through the initial decomposition time of RDX molecules was proposed. Compared to high-temperature thermal decomposition, the decomposition mechanisms and reaction pathways of some RDX molecules were different under electric fields. Compared to pure RDX systems, the addition of SWCNTs makes the charge values of some atoms in systems abnormal, weakening the bond energies of them and affecting the stability of the RDX system under electric fields, which is a key reason for enhancement of sensitivities of the electric field.