The Deryagin-Landau-Verwey-Overbeek DLVO Theory

The Deryagin-Landau-Verwey-Overbeek (DLVO) Theory 

The overall stability of a colloid will depend on the net form of the interaction energy curve for the system—the sum of the attractive and repulsive energy terms as a function of the distance of separation of the particles. For the moment, we will consider only two contributing factors the attractive van der Waals term and the repulsive double-layer term, leaving aside any consideration of entropic or steric stabilization. 

For a one-to-one electrolyte of valence z and bulk concentration Co, the excess charge density, p, at a point in the electrical double layer of potential ip is given by 

Poisson s equation of electrostatics relates pe to the variation of i/ with distance to the charged surface, x, in the form 

As previously shown, k is dependent on the concentration of ions in the system, and the primary concentration effect in Equation (10.32) comes from the exponential term. 

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THE DERYAGIN-LANDAU-VERWEY-OVERBEEK (DLVO) THEORY... 

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