Stability of dispersions

The importance of production and application of disperse systems in the industry is steadily growing. On the other site colloidale systems surround us every day (for example foodstuffs, pharmaceutica, and so on). With the knowledge about the mechanism of interaction forces we are able to develop new materials and improve available systems. The stability of such systems is one of the central point of research. One of the well known physical models of colloid stability is given by DLVO-Theory. With this theory we have a tool to influence the stability of such dispersion systems. In this paper electrokinetic methods are used to investigate interaction forces in disperse systems. The influence of pH-value, electrolyte concentration, and valency is shown. But, not in all cases the DLVO-model works satisfactoryly. Some reasons of this behavior will be discussed.