HOMOGENEOUS TO INHOMOGENEOUS TRANSITION IN CHARGED COLLOIDS

Using Monte Carlo simulations we report a homogeneous to inhomogeneous transition in colloidal dispersions as a function of surface charge d ensity of the particles and ionic strength. Homogeneous crystalline su spensions are found to develop voids coexisting with dense ordered and disordered structures beyond a critical charge density. The present r esults explain the reported experimental observations of stable voids in equilibrium with ordered and disordered structures, which suggest l ong-range attraction between the particles. The limitations of the the Derjaguin-Landau-Verwey-Overbeek potential are discussed in the light of the present results.