Ranges of frequency dispersion for the shear viscosity coefficients of aqueous solutions of electrolytes

The range of frequency dispersion for dynamic coefficient of shear viscosity η _S (ω) of electrolyte solutions obtained through kinetic equations under the condition of recovering the steady-state structure of a liquid exponentially or according to the diffusion law is considered. Numerical calculations of η _S (ω) are performed for an aqueous solution of NaCl depending on density ρ, temperature T, concentration C, and frequencies ω to select the potential of intermolecular interaction Φ _ab (|r|) and equilibrium radial distribution function g _ab (|r|). It is noted that the calculated theoretical results of η _S (ω) are in quantitative accordance with the experimental data. It is shown that the range of frequency dispersion η _S (ω) based on the diffusion mechanism is broad (～10⁵ Hz) and is narrow in the case of exponential attenuation of the viscous stress tensor (～10² Hz); this corresponds to both acoustic measurements and results from phenomenological theory.