Solubility Behavior, Hansen Solubility Parameters, and Thermodynamic Modeling of 9-Phenylcarbazole in 12 Monosolvents from 283.15 to 323.15 K

The mole fraction solubility of 9-phenylcarbazole in 12 pure solvents (isobutanol, sec-butanol, n-pentanol, isopentanol, ethyl lactate, dimethyl carbonate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate) was determined by the static gravimetric method at a temperature range of 283.15 to 323.15 K under a pressure of 101.2 kPa. The equilibrium solid phase of 9-phenylcarbazole in the solvent systems was characterized by powder X-ray diffraction analysis. The solubility in the 12 monosolvents was found to increase with absolute temperature. The maximum and minimum values were in isobutyl acetate and sec-butanol, respectively. The empirical solvent polarity parameters (E-T(30)), cohesive energy density, and hydrogen bond donor/acceptor (HBD/HBA) tendencies were used to analyze the solubility behavior and solvent effects. The solubility data were fitted using the modified Apelblat model, Margules model, NRTL model, Wilson model, and UNIQUAC model, and at the same time, the model parameters and data deviation values were calculated. The results showed that the modified Apelblat model had better correlation results. Furthermore, mixing thermodynamic characteristics of 9-phenylcarbazole in selected solvents were calculated by the NRTL model, which revealed that the mixing process was spontaneous and entropy-driven. The solubility data could be used in the preparation and optimization of 9-phenylcarbazole crystallization processes.