Measurement and correlation of solubility of o-vanillin in different pure and binary solvents at temperatures from 273.15 K to 303.15 K

• Published in: The Journal of chemical thermodynamics 2020-11, Vol.150, p.106199, Article 106199
• Main Authors: Mao, Haifang, Chen, Hong, Jin, Miaomiao, Wang, Chaoyang, Xiao, Zuobing, Niu, Yunwei
• Format: Article
• Language: English
• Subjects: Correlation; O-vanillin; Solubility; Thermodynamic properties
• ISSN: 0021-9614; 1096-3626
• DOI: 10.1016/j.jct.2020.106199

•An isothermal saturation method was used to test the solubility of o-vanillin.•Modified Apelblat equation was used to correlate the experimental solubility data.•The thermodynamic parameters, such as ΔHsolΔSsolΔGsol were achieved by van’t Hoff analysis.•Co-solvency and liquid-liquid phase separation phenomena was observed. The equilibrium solubility is the basis for purification and further theoretical studies of o-vanillin. In this paper, the solubility data of o-vanillin in three pure solvents, including water, ethanol, n-propanol, and two binary solvents of water + ethanol and water + n-propanol has been experimented under atmospheric pressure (p = 0.1 MPa) in the temperature range from 273.15 K to 303.15 K. The experimental results proved that the rising temperature leads to increased solubility of o-vanillin in all selected solvents. All the solubility data in different pure and binary solvents was correlated by the modified Apelblat equation. The computational values were in good agreement with the experimental results according to the calculations. In addition, some thermodynamic parameters of o-vanillin including dissolution enthalpy (ΔHsol), entropy (ΔSsol) and the Gibbs energy (ΔGsol) were obtained via the Van’t Hoff analysis. The positive values of ΔHsoland ΔGsolindicated that the dissolution process of o-vanillin is endothermic.