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

Abstract

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 ∞ 1 c v Q v = Ʃ ∞ 1 d v ζ v , where Qe denotes the charge on a sphere and ζ the zeta-potential; the coefficients c v and d v 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 c v and d v and the first four coefficients of each series found explicitly. Some quite general properties of the c v 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 .