A general theory of lyophobic colloids. II

Abstract

Abstract Corresponding to views developed in the first paper a formula is given, which roughly estimates the total energy of interaction between two colloidal particles as a function of their distance apart: this formula contains the particle charge E and the electrolyte concentration c as two independent parameters. The properties of a colloidal system are discussed for arbitrary values of E and c. The E‐c plane obtained by plotting E and c as abscis and ordinate in a rectangular system of axis is found to be split up in different portions; in one region a sol is stable, in another it is flocculated, while in intermediate regions more complicated conditions prevail. A physical change in the sol is represented by a simultaneous variation of E and c, that is by a curve in the E‐c plane. With the aid of such curves a variety of phenomena viz. peptisation, reversible and irreversible flocculation, and thixotropy are discussed in a clear and simple way.