DLVO theory

The DLVO theory is named after Derjaguin, Landau, Verwey and Overbeek who developed it in the 1940s.

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. For two spheres of radius a with constant surface charge Z separated by a center-to-center distance r in a fluid of dielectric constant ε containing a concentration n of monovalent ions, the electrostatic potential takes the form of a screened-Coulomb or Yukawa repulsion,

where λ_B is the Bjerrum length, κ ^{− 1} is the Debye-Hückel screening length, which is given by κ² = 4πλ_Bn, and β ^{− 1} = k_BT is the thermal energy scale at absolute temperature T.