FOX-7在H2O/DMF溶剂中的结晶形貌预测

为了准确理解溶剂和温度对含能材料结晶形貌的影响,采用分子动力学方法模拟研究了1,1-二氨基-2,2-二硝基乙烯(FOX-7)在水/二甲基甲酰胺(DMF)中的结晶形貌。构建了溶剂-晶面的界面吸附模型,使用修正附着能(MAE)模拟方法,计算溶剂-晶面之间的相互作用能,修正各晶面真空附着能并获得FOX-7在不同比例溶剂、不同温度条件下的晶习,分析了溶剂分子和FOX-7晶面之间的分子间作用力。结果表明:在真空条件下决定FOX-7晶习的六个重要晶面为(0 1 1),(1 0-1),(1 0 1),(1 1-1),(0 0 2)和(1 1 0)面;FOX-7在H2O/DMF溶液条件下的晶习随温度条件变化有明显差异,当温度为298K时在不同比例溶剂中的晶习均为块状,预测形貌与文献实验结果吻合较好。

Prediction of Crystal Morphology of FOX-7 in H2O/DMF Solvents

To accurately understand the effect of solvent and temperature on crystal morphology of energetic materials, molecular dynamics simulations were employed to investigate the crystal morphologies of 1, 1-diamino-2, 2-dinitroethene (FOX-7) under H₂O/dimethylacetamide (DMF) condition. By calculating the interaction energies of solvent and crystal surfaces, the attachment energies in vacuum were modified and the crystal shapes in different ratio of solvents with different temperatures were obtained. The intermolecular interactions of solvent molecules and crystal surfaces were also discussed. Results show that the morphologically dominant faces of FOX-7 in vacuum are (0 1 1), (1 0 -1), (1 0 1), (1 1 -1), (0 0 2) and (1 1 0), the crystal morphologies of FOX-7 in H₂O/DMF solutions are variable in different temperatures, the crystal shape is similar to block in different ratio of solutions in 298 K, and the predicted crystal morphology was in agreement with the experimental result from the reference.