ABSTRACT
The Gouy–Chapman model, the cornerstone of which is the Poisson–Boltzmann (PB) equation, has been the traditional approach for describing the electric double layer of colloids for many years. However, this mean-field theory ignores certain correlations that might produce wrong results in some cases. The nonmonotonic profiles observed in Monte Carlo (MC) simulations generally reveal types of ion layering. Surface heterogeneities can have considerable effects on electrokinetic properties or colloidal forces and computational methods also become a valuable tool to shed light on surface heterogeneity effects. Computer simulations can shed light on the validity of these ideas and, in any case, have actually proved that charge inversion can be explained without requiring any kind of specific adsorption if one goes beyond the PB approach. MC simulations have proved that the PB description of the EDL could be inadequate in the presence of multivalent ions.
