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, nD, 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, VmE, deviations in refractive indices, ΔϕnD, and deviations in molar refractions, ΔϕRM, 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,1E, V¯m,2E, were also computed. The Prigogine–Flory–Patterson theory and Graph theory were employed to correlate experimental VmE 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 VmE and negative values of ΔϕnD were observed, which suggests weak dispersion forces between dissimilar molecules.