of workers (21)(22)(23)(24)(25)(26). In all these analyses the entire surface Many surfaces encountered in colloid science are formed by the was considered to be of the constant charge or constant adsorption of surfactants or polymers on solid surfaces. Due to potential type. However, practical nonuniform surfaces, such the formation of surface aggregates, the charge distributions of as those formed by adsorption, may clearly possess regions such surfaces may be nonuniform. Furthermore, these surfaces are with different electrostatic properties, due to the presence of expected to have regions with different electrostatic properties due two or more different materials. Therefore, a model which to the presence of two or more different materials. In this paper, imposes the restriction that the surface is composed of matewe propose a model consisting of periodically alternating regions rials of only one type cannot be expected to display all the of constant potential and constant charge, in order to account for characteristics of such surfaces. In this paper we consider the possibility of different regions on the surface possessing different electrostatic properties. Specifically, we consider the behavior a surface composed of regions with different electrostatic of the far field effective electrostatic potential of this model surface properties. In particular, we consider a model surface conwhen it is immersed in an electrolyte, i.e., the potential associated sisting of periodically alternating regions of constant potenwith the asymptotic exponential tail of the potential distribution tial and constant charge, which is immersed in an electrolyte. in the electrolyte. In doing so, we find the previously unreported This model is the limiting case of a surface composed of phenomenon that the effective potential is strongly dependent on regions which are charge regulating in nature but whose the surface morphology and its associated length scale. Furtherquantitative properties vary spatially. The proposed model more, we find that there also exists the possibility that the constant displays features which are not present in previous models, charge regions will be ''invisible'' to the potential distribution. and as we shall discuss, gives an indication of what is to be These results have direct implications for general nonuniform expected from real nonuniform surfaces. charge regulating surfaces.