Influence of the temperature on the stability of aqueous alumina suspensions

Ceramic process need the preparation of very stable suspensions with high s olid loading and the temperature is a fundamental parameter in surface chem istry and at various steps in the production process. The influence of the temperature on the stability of aqueous alumina suspensions dispersed eithe r with the polymethacrylic acid sodium salt either with the Tron has been s tudied. The strong adsorption of the two dispersants onto alumina surface i s not affected by the variation of the temperature but temperature higher t han 40 degrees C strongly influences the amplitude of the repulsive potenti al created between the particules. By using the potentimetric data fitting software FITEQL 3.2, the electrokinetic properties of the suspensions at 20 degrees C are interpreted and viscosity measurements show that a temperatu re of 60 degrees C improves the stability of the suspensions and permits to concentrate it. (C) 1999 Elsevier Science Limited. All rights reserved.