Extended Poisson-Boltzmann descriptions of the electrostatic double   layer: implications for charged particles at interfaces
  The work reviews on a general level various modified Poisson-Boltzmann equations and demonstrates their use on the specific system of charged particles at an interface. This system is special, first, because it exhibits the long-range interactions on account of an air-water interface, and two, because the strength of these interactions depends on the structure of a double-layer. Thus, this system is particularly sensitive to the type of the modified Poisson-Boltzmann equation used. 
Derek Frydel and Martin Oettel
cond-mat.soft