Physical properties of a new dipeptide ionic liquid in water and methanol at several temperatures: Correlation and prediction

Abstract

The physical properties of choline glycylglycinate (ChGlyGly) were experimentally determined at several temperatures. The empirical values of density, refractive index, speed of sound and dynamic viscosity for aqueous and methanolic mixtures of this ionic liquid were also ascertained at different temperatures. From these values, isentropic compressibility, molar volume, free volume, isobaric thermal expansivity and molar refraction have been calculated along with critical parameters (temperature, volume and pressure), acentric factor and boiling point. From a theoretical point of view, derived values of the neat ChGlyGly and the corresponding mixtures have been ascertained in the abovementioned temperature interval. Polynomial fittings turned to suitably describe the obtained data while Redlich-Kister has been used to fit to the derived magnitudes. To conclude, the density of the mixtures has been successfully predicted at several temperatures for the first time by means of different models.