Charge titration data for silver iodide, titanium dioxide, aluminum oxide,
silica dioxide and ferric hydroxide are analyzed using a generic site bindi
ng model that has the Nernst equation as a limiting form. Both the hypernet
ted chain and the nonlinear Poisson-Boltzmann approximations are used to re
late the diffuse double-layer potential to the surface charge, and a zeroth
-order Stern layer is used to give the surface potential. In all cases it i
s shown that in the vicinity of the point of zero charge the Nernst equatio
n accurately gives the surface charge. (C) 2000 Academic Press.