在高速冲击下研究HMX的脱位和结对行为,采用分子动力学模拟
1School of Environmental and Safety Engineering, North University of China, Taiyuan, 030051, China.
Journal of molecular modeling
|January 24, 2024
概括
这项研究调查了冲击下的八-1,3,5,7-四-1,3,5,7-四素 (HMX),该研究发现双胞胎HMX分解得更快,产生更多的小分子和比完美或脱的HMX更少的.
科学领域:
- 计算材料科学 计算材料科学
- 化学动力学 化学动力学
- 爆炸物工程 爆炸物工程
背景情况:
- 了解像八-1,3,5,7-四-1,3,5,7-四素 (HMX) 这样的能量材料的冲击诱导分解对于安全性和性能至关重要.
- 晶体缺陷,如双胞胎和位移,可以显著影响爆炸物的灵敏度和分解路径.
- 之前的研究已经探讨了HMX分解,但在高速冲击下不同类型缺陷的具体影响需要详细调查.
研究的目的:
- 通过使用多尺度冲击技术 (MSST) 调查完美,脱位和双胞胎HMX的冲击诱导分解行为.
- 分析晶体缺陷对HMX灵敏度,键动态,小分子形成和在冲击下集群生成的影响.
- 将不同HMX晶体结构的分解特征进行比较,以了解缺陷介导的反应性.
主要方法:
- 使用Atomsk软件构建完美,双胞胎和脱的HMX晶体结构.
- 使用结合梯度 (CG) 算法和NVT/NPT模拟,对晶体模型进行几何优化和平衡.
- 使用ReaxFF/lg力场的大型原子/分子大平行模拟器 (LAMMPS) 进行11公里/秒的50秒多级冲击技术 (MSST) 冲击模拟.
主要成果:
- 双胞胎HMX表现出最高的灵敏度,而脱的HMX表现出最低的灵敏度,完美的HMX灵敏度与双胞胎相当.
- 双胞胎关系加速了键断裂,促进了小分子 (CO,H,NO,O) 的生成,并加速了NO的分解.
- 与完美和失位的HMX相比,双胞胎结构导致集群数量显著减少,这表明集群形成减少.
结论:
- 晶体缺陷,特别是双胞胎,显著改变了HMX.的冲击分解路径.
- 双胞胎HMX更敏感,并以不同的方式分解,产生更多的小碎片和更少的集群.
- 这些发现为控制高能材料的反应性和灵敏性的缺陷工程提供了洞察力.
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