Acta Chim. Sinica ›› 2018, Vol. 76 ›› Issue (7): 556-563.DOI: 10.6023/A18040153 Previous Articles     Next Articles

Article

梯恩梯(TNT)爆轰初期形成富碳团簇分子及类石墨结构的分子动力学模拟

张亚平a, 杨镇a, 李启凯b, 何远航a   

  1. a 北京理工大学 爆炸科学与技术国家重点实验室 北京 100081;
    b 北京科技大学 新金属材料国家重点实验室 北京 100083
  • 出版日期:2018-07-15 发布日期:2018-05-21
  • 通讯作者: 何远航,E-mail:heyuanhang@bit.edu.cn;Tel.:010-68918878 E-mail:heyuanhang@bit.edu.cn

Carbon-rich Clusters and Graphite-like Structure Formation during Early Detonation of 2,4,6-Trinitrotoluene (TNT) via Molecular Dynamics Simulation

Zhang Yapinga, Yang Zhena, Li Qikaib, He Yuanhanga   

  1. a State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081;
    b State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083
  • Online:2018-07-15 Published:2018-05-21
  • Contact: 10.6023/A18040153 E-mail:heyuanhang@bit.edu.cn

The clusters can be seen in carbon-rich explosives during detonation. However, we can't directly observe the formation of clusters by experimental methods. The thermal decomposition of TNT at various temperatures are studied using ReaxFF/lg molecular dynamics simulations. The ReaxFF/lg force field provides detailed information on the formation of cluster from atomic level, the stability of the clusters and the graphite-like structures. The results show that clusters formed slowly at the initial reaction with increasing the relative molecular mass of a TNT approximately one time. As the reaction proceeding, the mass of clusters increases rapidly, and the molecular weight of max cluster can reach 8000~10000 (amu), accounting over about 18% of the system mass. Analysis of the structure of the clusters reveal that some benzene rings in the clusters were broken, and five-membered rings and the six-membered rings which contain N and O atoms were formed, and the more complex seven-membered rings structure were formed under the 3500 K condition. Through the method of linear expansion and direct cooling, the stability of the clusters was studied:the clusters decomposed rapidly by the method of linear expansion, while the clusters aggregated into larger clusters by the method of direct cooling. Through the analysis of graphite-like structures, we obtain that it is an essential step to first expand and the cool down second by analysis the production process of graphite-like structures. The mass ratio of C atoms in the clusters has been increasing during the reaction process by comparing the ratio of the mass of each atom in the clusters and TNT molecules, while the mass ratio of N atoms and H atoms in the clusters decrease and the mass ratio of O atoms show more complicated during the whole reaction. This study can provide a good basis for the preparation of new nanomaterials for detonation of TNT.

Key words: carbon-rich explosive, cluster, Reaxff/lg, graphite-like, volume expansion