Determination of hydration parameter h for sugars with a large number of equatorial OH groups and development of a simple method for measuring h using a vibration viscometer

Abstract

The hydration parameter h was obtained from the viscosity B-coefficients using capillary viscometers (CVs) and the partial molar volume, V₂, for sugars with a large number of equatorial (e) OH groups in aqueous solutions at 25 °C. The B-coefficient reflects the effect of a solute on water-structure, considering the Einstein exclusion effect. V₂ values were estimated via extrapolation of the apparent molar volumes. Parameter h showed a good correlation (R² = 0.979) with the number of e-OH groups, even when large numbers of e-OH saccharides were added. Given the time-consuming nature of h measurement, a vibration viscometer (VV) was also used to calculate the B-values. Despite the higher relative viscosity at high concentrations estimated using the VV compared with the CV, the B-values were comparable. Thus, a simple, time-saving, and cost-effective method for measuring h using a VV has been established.