THE VARIATION OF CATIONIC ACTIVITY IN COLLOIDAL CLAYS WITH CONCENTRATION OF THE DISPERSE PHASE

The variations of the activity of Na+, K+ and Ca2+ ions of clays, saturated with these ions, have been determined at various concentrations of the clays by means of clay-membrane electrodes. The ionic activities increase almost linearly up to a certain concentration of the clay (11%, 10% and 5% for Na-, K- and Ca- clays respectively) but afterwards the rate of increase slows down. The percentage dissociation of Na- and K- clays decreases sharply at first; followed by an increase, and a more or less flattened maximum at about Ca- clay, however, shows no initial decrease in dissociation which rises to a fairly sharp maximum at about 2.2% clue concentratio