Solubility Measurement and Thermodynamic Properties of Fluorene in 14 Pure Solvents at Temperatures from 278.15 to 318.15 K

In this study, the solubility data of fluorene in 14 pure organic solvents (methanol, ethanol, n-propanol, isopropanol, ethyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, propanone, acetonitrile, and tetrahydrofuran) from 278.15 to 318.15 K were measured using a gravimetric method at atmospheric pressure. Four thermodynamic models, including the modified Apelblat model, ?h model, van't Hoff model, and NRTL model, were employed to correlate solubility data and further evaluated by the average relative deviation (ARD). The experimental results revealed a positive correlation between solubility and temperature. ARD values of four models were less than 4%, indicating that all models had good correlations. Among them, the modified Apelblat model had the best correlation. Mixing thermodynamic properties were calculated based on the NRTL model. Results showed that the dissolution process was a spontaneous entropy-driven process. In addition, the solubility of fluorene decreased with increasing solvent polarity, cohesive energy density, and steric hindrance after solvent effect analysis.