Volumetric, Optical, and Spectroscopic Study of Molecular Interactions for Binary Liquid Mixtures of Gamma-Valerolactone with 2-Alkoxyethanols

Abstract

Physical parameters such as densities, ρ, and refractive indices, n D , of pure gamma-valerolactone/2-alkoxyethanols and their binaries have been determined over the whole composition range at different temperatures (298.15, 303.15, 308.15, and 313.15 K) and pressure = 0.1 MPa. From the experimental results, excess properties such as excess molar volumes, V m E , deviations in refractive indices, Δ ϕ n D , and deviations in molar refractions, Δ ϕ R M , have been calculated. The predicted data were fitted to the Redlich−Kister-type polynomial equation to derive the binary interaction parameters and recognize standard deviations between experimental and calculated values of the liquid solutions. Furthermore, the partial molar volumes, V m,1 , V m,2 , and excess partial molar volumes, V m,1 E , V m,2 E , were also computed. The Prigogine−Flory−Patterson theory and Graph theory were employed to correlate experimental V m E values. The departure of real mixtures from ideal behavior was interpreted in terms of strength and nature of molecular interactions. Furthermore, Fourier-transform infrared spectroscopy studies of the investigated solution along with pure components were also reported to obtain a better insight into intermolecular interactions between unlike molecules. In our study, positive values of V m E and negative values of Δ ϕ n D were observed, which suggests weak dispersion forces between dissimilar molecules.