文摘
A new model for the viscosity of electrolyte solutions has been developed based on the combinationof liquid-state theory and absolute-rate theory. Using the McMillan-Mayer framework, the ionsare represented as charged hard spheres and the solvent as a continuum. The activationHelmholtz energy in absolute-rate theory is approximated by the equilibrium mixing Helmholtzenergy calculated analytically from liquid-state theory with a mean spherical approximation.The new model can satisfactorily correlate all available experimental viscosity data up to 12mol/L of 20 alkali-halide aqueous solutions at ambient conditions with an overall average relativedeviation (ARD) of only 0.29%, while the Kaminsky equation yields an overall ARD of 0.81%with the same number of adjustable parameters. Both monotonic and anomalous concentration-dependent viscosity behavior are well described quantitatively. The adjustable parameters inthe model have physical meaning and are related with the degree of ion hydration, in agreementwith the Hofmeister series. The simplicity and accuracy of this new model make it particularlywell suited for engineering applications.