Abstract
The dipolar mechanism of long range like-charge attraction between colloidal particles in aqueous solution depends on the inhomogeneity of their surface charge distribution. We propose a computational model compatible with the mean field theory (Gouy-Chapman-Stern model) that can be used to study the effect of short range lateral interaction among surface groupheads on the formation of charge inhomogeneity during the dissociation process. From this model, it seems that when lateral interaction is taken into account, charge inhomogeneity is common in the presence of weak impurity potential about a few k_BT, which by itself has no such effect.