ABSTRACT
Model ..................................................................... 53 III. Repulsion Between Planar Surfaces:
DLVO Theory................................................................ 54 IV. The Zeta Potential........................................................ 57 References.............................................................................. 68
I. INTRODUCTION
Surface charges play an important role in translocation and aggregation processes. The following treatment is restricted to uniformly charged particles immersed in ideally diluted electrolyte solutions. After treating the Gouy-Chapman theory of an isolated planar charged surface, we will consider the DLVO theory (named after Derjaguin, Landau, Verwey, and Overbeek) describing, in an approximate manner, the interaction between two identical charged surfaces. The theory incorporates electro-osmotic repulsion (which is due to the ionic cloud between the particles) and van der Waals attraction. After these thermodynamic considerations we turn to electrokinetics and consider the electrical potential of the surface of shear (called the zeta potential) of particles moving under the influence of a uniform external electrical field. An attempt is made to work out the theoretical background of the equations commonly used in practice.
