Key Laboratory of Soft Chemistry and Functional Materials of MOE, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
Phys Chem Chem Phys. 2018 May 23;20(20):14192-14199. doi: 10.1039/c8cp01621f.
Molecular dynamic simulation of a high explosive, RDX, mixed with AlH3 nanoparticles was performed by a newly parameterized ReaxFF force field. Testing of the ReaxFF shows that the mean absolute errors of the densities and bond lengths between calculated and experimental values are less than 7% and 3%, respectively. Using the ReaxFF, effects of AlH3 nanoparticles with different radii on the thermal decomposition of RDX were revealed. A new mechanism of the generation and the consumption of H2 was discovered in the explosion. The H2 is released by AlH3 firstly and then it reacts with NO2 and CO2 from the decomposition of RDX, leading to an increase of H2O, NO and CO. Meanwhile, the size effect of AlH3 upon the reaction was also revealed. As a result, the number of produced H2O and CO2 molecules increases by 10.38% and 56.85%, respectively, when the radius of AlH3 nanoparticles decreases from 1.10 to 0.68 nm. This showed that RDX decomposes more completely with smaller AlH3 nanoparticles, which was further demonstrated by the analysis of reaction residues and diffusion coefficients.
采用新参数化 ReaxFF 力场对含 AlH3 纳米颗粒的高爆炸药 RDX 进行了分子动力学模拟。ReaxFF 的测试表明，计算值与实验值之间的密度和键长的平均绝对误差分别小于 7%和 3%。利用 ReaxFF，揭示了不同半径的 AlH3 纳米颗粒对 RDX 热分解的影响。在爆炸过程中发现了 H2 的生成和消耗的新机制。首先，AlH3 释放 H2，然后它与 RDX 分解产生的 NO2 和 CO2 反应，导致 H2O、NO 和 CO 的增加。同时，还揭示了 AlH3 的尺寸效应对反应的影响。结果表明，当 AlH3 纳米颗粒的半径从 1.10nm 减小到 0.68nm 时，产生的 H2O 和 CO2 分子数分别增加了 10.38%和 56.85%。这表明较小的 AlH3 纳米颗粒使 RDX 分解得更完全，这通过反应残留物和扩散系数的分析进一步得到证实。
