Influence of the temperature on the stability of aqueous alumina suspensions

Ceramic process need the preparation of very stable suspensions with high solid loading and the temperature is a fundamental parameter in surface chemistry and at various steps in the production process. The influence of the temperature on the stability of aqueous alumina suspensions dispersed either with the polymethacrylic acid sodium salt either with the Tiron has been studied. The strong adsorption of the two dispersants onto alumina surface is not affected by the variation of the temperature but temperature higher than 40°C strongly influences the amplitude of the repulsive potential created between the particules. By using the potentimetric data fitting software FITEQL 3·2, the electrokinetic properties of the suspensions at 20°C are interpreted and viscosity measurements show that a temperature of 60°C improves the stability of the suspensions and permits to concentrate it.