Elucidation of the crystal nucleation process can provide guidance for controlling crystal size and quality. To understand the nucleation process of 1,1-diamino-2,2-dinitroethylene (FOX-7), the induction time and nucleation kinetics of FOX-7 were studied using a turbidity method in a binary solvent system (DMSO ​+ ​water, x_DMSO ​= ​0.3364) under cooling crystallization conditions. Using the CrystalSCAN system, the induction time was determined at a range of temperatures (325.05, 335.25, 343.15, 348.15, and 354.65 ​K) and supersaturations (S) (1.20, 1.22, 1.24, 1.27, 1.30, 1.32, 1.35, 1.37), and it was found that induction time decreases as supersaturation increases. The system displayed a homogeneous nucleation mechanism at high supersaturation ratios (≥1.27) and heterogeneous nucleation at low supersaturation ratios, below 1.25. The FOX-7 crystal exhibited a continuous growth mechanism, as inferred from the value of the surface entropy factor (f). The induction time data were analyzed using the classical nucleation theory to calculate the interfacial energy (γ) and various nucleation parameters, including the radius of the critical nucleus (r∗), critical free energy of the nucleus (ΔG∗), molecular number of the critical nucleus (i∗), and the nucleation rate (J). The morphology of FOX-7 crystals changed negligibly with varying temperature and supersaturation, while the average particle size decreased with an increase in supersaturation and a decrease in temperature.

晶体成核过程的阐明可为控制晶体尺寸和质量提供指导。为了了解1,1-二氨基-2,2-二硝基乙烯（FOX-7）的成核过程，使用浊度法在二元溶剂系统（DMSO +水）中研究了FOX-7的诱导时间和成核动力学。 ，x _DMSO  = 0.3364）在冷却结晶条件下。使用CrystalSCAN系统，在一定温度范围（325.05、335.25、343.15、348.15和354.65 K）和过饱和度（S下确定诱导时间）（1.20、1.22、1.24、1.27、1.30、1.32、1.35、1.37），发现诱导时间随着过饱和度的增加而减少。该系统在高过饱和比（≥1.27）下显示均相成核机制，在低过饱和比（低于1.25）下显示出异相成核。从表面熵因子（f）的值推断，FOX-7晶体表现出连续的生长机理。使用经典成核理论分析诱导时间数据，以计算界面能（γ）和各种成核参数，包括临界核的半径（r ∗），原子核的临界自由能（ΔG ∗），分子数临界晶核的（我∗），成核率（J）。随着温度和过饱和度的变化，FOX-7晶体的形态变化可忽略不计，而平均粒径随着过饱和度的增加和温度的降低而减小。