Interaction of cationic and anionic polyelectrolyte with SiO2 and Al2O3 powders

The adsorption of anionic and cationic polyelectrolytes onto alumina and silica surfaces is studied. The results indicate that the polyelectrolyte-surface interaction is affected by various factors such as (i) polyelectrolyte nature, (ii) distribution and nature of the oxide surface sites, and (iii) medium properties. A strong interaction enhances the formation of a flat conformation of the adsorbed polyelectrolyte onto the surface, whereas a weak interaction leads to a loops conformation. The effect of the adsorbed polyelectrolyte on the electrokinetic behaviour of the two oxides was also investigated using an electrokinetic sonic amplitude analyser.