Electrophoretic mobility of highly charged macroions in aqueous electrolytes with multivalent coions

According to the dominance prescription of point-ions in the non-linear Poisson-Boltzmann theory, proposed by Valleau and Torrie more than 30 years ago, the equilibrium microscopic and thermodynamic properties of an asymmetric binary electrolyte converge asymptotically to those of a completely symmetric electrolyte, in the limit of an infinite colloidal surface charge density, if the properties of the counterions are the same in both instances. In order to determine if such a dominance can be observed dynamically, in this work we study the electrophoretic mobility of highly charged spherical colloids immersed in several 1:z electrolytes, when the counterions have the same properties. We observe that there is an inversion in the precedence order of the electrophoretic mobilities as a function of the surface charge density of the macroions. Moreover, our theoretical calculations based in the Wirsema, O'Brien and White theory suggest that, in the limit of an infinite colloidal charge density, the electrophoretic mobility does not converge to the same value for different valences of coions even if the monovalent counterions have the same properties.