Effects of Sodium and Potassium Ions on the Viscosities in the Sodium/ Potassium-Glucose-Water Ternary System

摘要

Sodium ions and potassium ions, are important in the activity of living bodies. Despite the chemical similarities of these ions, their cellular distributions are different and asymmetric; the external concentration of sodium ions exceeds their intracellular concentration and the reverse is true for potassium ions. To clarify the role of each ion in living bodies, the physicochemical properties of each ion has been studied in the alkali halide–saccharide--water ternary system. The viscosity of sodium (NaCl)- or potassium (KCl)-glucose-water with varying concentrations was investigated in this study. The density of the NaCl- or KC1-glucose-water ternary system was measured with a Gay-Lussac–type pycnometer. The flow time of the ternary system was mea-sured with an Ubbelohde viscometer. The viscosity of the solutions was calculated from the density and the flow time. All measurements were conducted at 25° ± 0.01°C. The concentration of the NaCl-KCI-glucose solution used in this study was expressed in molar ratios (nalkali-metal saltlnwater and nglucose/nwater, where n is the number of moles). The concentrations of NaCl, KCl, and glucose in water were nNaCl/nwater = 0.00018, 0.00090, and 0.00181; nKCl/nwater = 0.00018, 0.00090, and 0.00181; and nglucose/nwater = 0.0009, 0.0018, 0.0099, 0.016, 0.022, and 0.030. For the NaCl-glucose-water system, the relative viscosity increases with increasing NaCl concentration. The results for KCl are more complex. When the glucose con-centration is less than 0.0018, the relative viscosity increases with increasing KCl concentration, whereas when the glucose concentration exceeds 0.0099, the relative viscosity decreases with increasing concentration. A similar change in the dependence of relative viscosity on KCl concentration is seen in the binary KC1-water system as a function of temperature.