Exploring hydrophobic eutectic solvents based on raspberry ketone

Hydrophobic Eutectic Solvents (HES) have been drawing attention over the last decade, since they offer a green possibility of replacing volatile organic solvents derived from fossil sources. This work focuses on the development of new HES based on raspberry ketone (RK). COSMO-RS (COnductor-like Screening MOdel for Real Solvents) was used to screen hydrophobic compounds to be used in HES formation with RK. Afterwards, the solid-liquid equilibrium was experimentally measured for RK and four selected compounds, DL-Menthol, Thymol, Lidocaine and Flavone, using visual turbidimetry and Differential Scanning Calorimetry. UNIversal QUAsi-Chemical (UNIQUAC) model was used to model the experimental data and validate both the experimental data and COSMO-RS results. Thermophysical properties, density and viscosity, of the prepared HES were measured, in a temperature range between 40 °C and 80 °C, for selected compositions that were liquid at room temperature. The polarity of these liquid at room temperature HES was also quantified using Kamlet-Taft and betaine dye scales. Finally, the water mutual solubility was also experimentally measured so that conclusions can be drawn about their HES hydrophobicity.