Thermodynamic and physicochemical characteristics of 2-butoxyethanol/2-phenoxyethanol in aqueous maltitol solutions

Abstract

In this study, interactions occurring among solute and solvent in aqueous solutions containing maltitol and 2-butoxyethanol (2-BE) and 2-phenoxyethanol (2-PhE) as a solute were studied (Viz volumetric, acoustic and spectroscopic study). Density, ρ, and speed of sound,s, of 2-BE and 2-PhE in aqueous solutions of maltitol with concentrations (0.01, 0.02, and 0.03) mol∙kg-1 were measured at various temperatures ranging from 288.15 K to 308.15 K at 0.1 MPa.The data was used to calculate acoustic and thermodynamic parameters, such as the apparent molar volume (Vϕ), apparent molar isentropic compression (Kϕ,s), partial molar volume (Vϕ0) and partial molar isentropic compression at infinite dilution (Kϕ,s0). This analysis helped us understand the solvation behaviour of maltitol, which is a key component in sugar-free products. Additionally, the co-sphere overlap model was used to examine several intermolecular interactions in the ternary systems. We investigated the partial molar expansibilities (Eϕ0) and their first-order derivatives ∂Eϕ0/∂Tp to examine the solute's structure-making and structure-breaking properties. Finally, we also carried out spectroscopic studies for both binary and ternary mixtures. The observed molar properties indicate the presence of significant interactions between the solute and solvent components within the ternary mixture. This is further supported by the positive values of partial molar expansibility. Moreover, the partial molar properties of the mixture strongly imply the occurrence of hydrogen bond formation.