Physico-chemical study on the solvation characteristics of sodium gluconate in aqueous β-cyclodextrin solutions at T= (298.15-318.15) K

• Densities and viscosities of sodium gluconate in aqueous β-cyclodextrin solutions reported. • Ultrasonic speed of sound of sodium gluconate in aqueous β-cyclodextrin solutions reported. • Concentration & temperature dependence of some thermodynamic parameters discussed. • Viscosity B -Coefficients of sodium gluconate in above solutions were also investigated. • Solute-solvent and solute-solute interactions were studied using above parameters. • Sodium gluconate acts as a water structure promoter as reflected by the positive ( ∂ φ E 0 / ∂ T ) P values. Densities, viscosities and ultrasonic speeds of sodium gluconate in various aqueous molal solutions [ m = (0.005-0.020) mol.kg -1 ] of β-cyclodextrin were measured at T = (298.15-318.15) K and ambient pressure P =101 kPa. Several volumetric, viscometric, thermoacoustic and thermodynamic properties have been determined from the measured data like apparent molar volumes, standard partial molar volumes, apparent specific volumes, standard isobaric partial molar expansibilities and their temperature dependence, viscosity B -coefficients and solvation number, etc . Further, the standard volumes of transfer for sodium gluconate from water to aqueous β-cyclodextrin solutions were derived in order to have insights into the molecular interactions in the ternary solutions and the effects of molality, solute structure and temperature and taste behavior were examined. These findings showed that sodium gluconate acts as a structure maker and that the solute-solvent or ion-solvent interactions dominate in the ternary solutions. 1 H NMR spectroscopic and computational studies were performed to substantiate these findings.