Melting Point Prediction of Energetic Materials via Continuous Heating Simulation on Solid-to-Liquid Phase Transition

• Published in: ACS omega 2019-02, Vol.4 (2), p.4320-4324
• Main Authors: Liu, Yingzhe, Lai, Weipeng, Yu, Tao, Ma, Yiding, Guo, Wangjun, Ge, Zhongxue
• Format: Article
• Language: English
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.8b03597

Melting point is a significant property of energetic materials especially for melting cast explosives. Theoretical prediction of melting point is greatly meaningful for design and screening of low-melting-point candidates for casting medium. Herein, the melting behavior of nitromethane (NM) at different heating velocities ranging from 1 to 0.02 K/ps was investigated via molecular dynamics simulation of solid-to-liquid phase transition as a case study. Simulation results indicate that stable solid-to-liquid phase transition can occur when the heating velocity is less than or equal to 0.1 K/ps. The melting point of NM was predicted to be around 254 K, which is in reasonable agreement with the experimental value of 245 K. In the melting process, the structural transition from ordered arrangement to disordered distribution of NM molecules was observed as a result of the weakening of intermolecular interactions, leading to the decrease of C–H···O hydrogen bonds. The results reported here shed light on the important influence of heating velocity on accurate estimation of melting point in continuous heating simulations.