Solubility measurement and correlation for HNIW·TNT co-crystal in nine pure solvents from T = (283.15 to 318.15) K

Abstract The solubility of HNIW·TNT co-crystal was measured in acetonitrile, ethyl acetate, methanol, ethanol, m-xylene, chloroform, butanone, toluene, and 1,2-dichloroethane from 283.15 to 318.15 K under atmospheric pressure by using a gravimetric method. The results show that the solubility of HNIW·TNT co-crystal increase with increasing temperature in nine pure solvents. Within the experimental temperature range, the average solubility of HNIW·TNT co-crystal was recorded as the maximum data in acetonitrile (12.53 × 10−2) and the minimum data in ethanol (0.20 × 10−2). The modified Apelblat equation, van't Hoff equation, Yaws model, and λh equation were used to correlate the solubility of HNIW·TNT co-crystal in nine pure solvents, and the modified Apelblat equation and Yaws model showed satisfactory accordance with the experimental data. Furthermore, the thermodynamic parameters including the enthalpy change (∆Hsol°), the entropy change (∆Ssol°), and the Gibbs free energy change (∆Gsol°) were also calculated, indicating the dissolution behavior of HNIW·TNT co-crystal in nine pure solvents is an endothermic and non-spontaneous process. The results may supply basic theoretical guidance for optimizing the crystallization process of HNIW·TNT co-crystal.