ON THE ISOTHERM FOR IONIC ADSORPTION FROM SOLUTION By

The method of the Fourier-Bessel integral has been used to calculate the electrostatic image energy in the solution and to examine the effect on this quantity of diffuseness of the dielectric barrier in the double layer. The present diffuse dielectric boundary model shows an imaging energy in solution some 40 times less than that for a sharp boundary. The multiple energy is only 1 % more than that of the single imaging in the metal. An isotherm is deduced. The model used is the imaging in the metal; coulombic and dispersive interaction energies for the adsorbed ions are calculated without approxi-mation; Flory-Huggins statistics are used. The capacitance charge curve is interpreted quantitatively with respect to the phenomenology of the capacitance hump and minimum. The hump is not significantly affected by the variation of the integral capacity with potential. The failure of the water model for capacitance hump is rationalized. The multiple imaging approximation using a sharp dielectric boundary does not predict a capacitance minimum (anodic) but predicts a capacitance hump which is in discrepance with experiment in respect to the ionic dependence and temperature