INTERACTION OF DISSIMILAR PLANE PARALLEL DOUBLE LAYER AT ARBITRARY POTENTIAL

Several elliptic integrals related to the interaction energy between two dissimilar parallel plates (the potentials on the two plates are of the same sign) are expanded in several fast convergent series for lower and higher surface potentials, respectively. The number of series terms required to obtain the interaction energy with six significant figures is not more than four for the dimensionless surface potential from 0 to 20 if the series fit for the lower potential is combined with the series fit for the higher potential. The approximate expressions with different precisions can be obtained by retaining different series terms. The results of Devereux and de Bruyn are discovered to be incorrect when the surface potential is very low or very high.