The cataphoresis of spherical, solid non-conducting particles in a symmetrical electrolyte

A theoretical analysis is given of the motion of solid non-conducting charged spheres through symmetrical electrolytes, under the action of an applied electric field. It is shown that the steady velocity of translation U may be written in the alternative forms U = Ʃ∞1cvQv = Ʃ∞1dv ζv, where Qe denotes the charge on a sphere and ζ the zeta-potential; the coefficients cv and dv are proportional to the applied field strength and depend upon the radius of the particle and the concentrations, valencies and mobilities of the ions in the electrolyte. A general method is given for calculating the cv and dv and the first four coefficients of each series found explicitly. Some quite general properties of the cv are also deduced. It is shown that under certain conditions, the terms of the series for U, apart from the first, are of considerable importance and must be taken into account in estimating ζ from U.