Stable colloids at the isoelectric point: Dipolar vs. electrostatic interactions

The strange stability of some colloid systems at the isoelectric point may be explained by interparticle electrostatic interactions (attractive and repulsive) of different electric charge patches on the particles’ surface, related to differences of their surface structure and possibly to adsorption of charged species on them. The coincidence of the minimum colloid stability with the electro-optically observed minimum of the particle electric...