Investigation of the thermodynamic and physicochemical properties of lavender oil (Lavandula angustifolia Mill.)-ethanol-water system

The thermodynamic and physicochemical properties of lavender oil (Lavandula angustifolia Mill.)-ethanol-water system were measured. The chemical composition of solutions of the lavender oil in 70%, 75%, 80%, 85%, 90%, and 95% ethanol was determined using GC/MS analysis. The main compounds in the solutions are oxygenated monoterpenes (β -linalool, terpinen-4-ol, α -terpineol, and linalyl acetate), followed by monoterpene hydrocarbons ((Z)-β -ocimene and (E)-β -ocimene), and sesquiterpene hydrocarbons (β -caryophyllene and (E)-β -farnesene). The ternary phase diagrams were constructed. By multiply linear regression model for surface tension prediction was applied. The thermodynamic and kinetic parameters of lavender oil – ethanol - water system were calculated (energy of Gibb’s, enthalpy, entropy, energy of activation, and coefficient of diffusion).