Thermodynamic Properties and Synergistic Interactions in the IL-PSI–Sugar–Water System: Hydrogen-Bond Network Enhancement and Microstructural Strengthening

This work examines the thermophysical properties, (density, volumetric properties, electrical conductivity, viscosity) of the 1-ethyl-3-methylimidazolium diethyl phosphate (IL-PSI)–sugar–water system at 298.15 K. Experimental density (ρ) and viscosity (η) data were analyzed using the Redlich–Mayer and Jones–Dole equations to obtain the apparent molar volume (VΦ) and the viscosity B-coefficient, respectively. Kohlrausch’s law was used to determine the limiting molar conductivity (Λ0), and the Walden product (Λ0η0) was subsequently calculated. Critical aggregation concentrations were identified through conductometric measurements, and the related aggregation thermodynamics were quantified via a pseudophase model. Through this thermodynamic analysis, solute–solute and solute–solvent interactions were probed to shed light on the microscopic organization of these systems.