An Effect of X-Radiation on the Potential of Colloidal Graphite

Abstract

IN the course of our attempts to elucidate the nature of the action of X-rays on colloids, we have been investigating the effect of irradiation on the ζ potential of the colloidal particles. The sol selected for the preliminary experiments was an artificial graphite dispersed in conductivity water with the aid of traces of ammonia. This sol is practically homogeneous towards X-radiation, and has a low electrolytic content. It is stable, and the ζ potential of a given stock shows no significant changes over a period of four months. The ζ potential is deduced from measurements on the electrophoretic velocity of the particles. The experimental technique employed in our laboratory has been fully described by Lane and White¹, who have shown that the probable error of a single observation is of the order of 2½ per cent.