Application of the symmetric Poisson-Boltzmann theory to a model colloidal mixture.

A symmetric Poisson-Boltzmann theory is used to analyse the structure of a primitive model colloidal system which contains either 4 or 6 components. The approach symmetrizes the pair distribution function () between two asymmetric charged species with respect to an interchange of the indices. Good agreement is found with molecular dynamics simulation structural properties when the exclusion volume term is modelled by the Percus-Yevick uncharged hard sphere radial distribution function.

On the modified Poisson-Boltzmann closure for primitive model electrolytes at high concentration.

The modified Poisson-Boltzmann closure is applied to the Kirkwood hierarchy of integral equations to investigate high concentration primitive model electrolytes. Two approximations are considered in the two sphere fluctuation potential problem. The derived damped oscillatory mean electrostatic potentials suggest that this closure should be of use in providing a basis for understanding the large experimental decay lengths found at high electrolyte concentrations.

The planar electric double layer capacitance for the solvent primitive model electrolyte.

The planar electric double layer capacitance of the solvent primitive model electrolyte is studied using simulation and two versions of the modified Poisson-Boltzmann theory. At small values of the surface charge and varying electrolyte concentration, the capacitance has a behaviour analogous to that of the restricted primitive model electrolyte. As the electrolyte concentration is increased at a fixed total packing fraction, the minimum at zero surface charge changes to a maximum.

A MODIFIED POISSON-BOLTZMANN STUDY OF THE SINGLET ION DISTRIBUTION AT CONTACT WITH THE ELECTRODE FOR A PLANAR ELECTRIC DOUBLE LAYER.

The properties of the singlet ion distributions at and around contact in a restricted primitive model double layer are characterized in the modified Poisson-Boltzmann theory. Comparisons are made with the corresponding exact Monte Carlo simulation data, the results from the Gouy-Chapman-Stern theory coupled to an exclusion volume term, and the mean spherical approximation. Particular emphasis is given to the behaviour of the theoretical predictions in relation to the contact value theorem involving the charge profile.

The electric double-layer differential capacitance at and near zero surface charge for a restricted primitive model electrolyte.

The behavior of the differential capacitance of a planar electric double layer containing a restricted primitive model electrolyte in the neighborhood of zero surface charge is investigated by theory and simulation. Previous work has demonstrated that at zero surface charge the differential capacitance has a minimum for aqueous electrolytes at room temperature but can have a maximum for molten salts and ionic liquids. The transition envelope separating the two situations is found for a modified Poisson-Boltzmann theory and a Poisson-Boltzmann equation corrected for the exclusion volume term.