VII – General Causes for Degradation and Relative Stability of Lyophobic Colloidal Systems

Publisher Summary Lyophobic colloidal systems are coarse and fine disperse systems that are thermodynamically unstable because of a substantial excess in surface free energy. The latter may be related both to the existence of highly developed interface between the dispersed phase and the dispersion medium, and to relatively high values of interfacial tension, σ. This excess of the surface free energy is the reason for instability of such systems in which various processes leading to a coarsening and finally to complete degradation of systems, that is, separation into individual macroscopic phases take place. General stability of lyophobic colloidal systems, as well as the rate of processes leading to degradation, is determined by nature, phase state, and composition of the dispersed phase and dispersion medium, and also by the degree of dispersion and concentration of the dispersed phase. Stability of disperse systems may vary in a very broad range from complete instability to nearly infinite stability.