Abstract
We present a versatile theoretical method for calculating the steady-state viscosity and shear relaxation function of strong electrolyte solutions. In this method, the ions are described on a primitive model level as charged Brownian spheres, and the essential ion–ion hydrodynamic interactions (HIs) are accounted for in the shear relaxation effect of the ionic atmosphere. The method combines a many-component mode-coupling theory (MCT) approach by Nägele et al (1998 J. Chem. Phys. 108 9893) with a simplified solution scheme, leading to an analytic expression for the shear relaxation contribution to the viscosity. This expression accounts for both the excluded volumes of the ions and their HIs. We show that the limiting law results for the viscosity of electrolyte mixtures by Falkenhagen and by Onsager and Fuoss are recovered at very low concentrations, and we discuss HIs corrections appearing at higher concentrations. Our numerical results for a 1:1 electrolyte reveal a strong enlargement of the viscosity caused by the HIs. The high-frequency viscosity gives the largest contribution to the total viscosity at higher concentrations.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
