DLVO Theory

DLVO Theory

The DLVO theory is named after Derjaguin and Landau, Verwey and Overbeek.

The theory describes the force between charged surfaces interacting through a liquid medium. It combines the effects of the van der Waals attraction and the electrostatic repulsion due to the so called double layer of counterions. The electrostatic part of the DLVO interaction is computed in the mean field approximation in the limit of low surface potentials - that is when the potential energy of an elementary charge on the surface is much smaller than the thermal energy scale, . For two spheres of radius each having a charge (expressed in units of the elementary charge) separated by a center-to-center distance in a fluid of dielectric constant containing a concentration of monovalent ions, the electrostatic potential takes the form of a screened-Coulomb or Yukawa repulsion,

\beta U(r) = Z^2 \lambda_B \, \left(\frac{\exp(\kappa a)}{1 + \kappa a}\right)^2 \, \frac{\exp(-\kappa r)}{r},

where is the Bjerrum length, is the Debye-Hückel screening length, which is given by, and is the thermal energy scale at absolute temperature .

Read more about DLVO Theory:  History, Derivation of DLVO Theory, Application of DLVO Theory, Shortcomings of The DLVO Theory

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