Previous work has shown that certain cationic solutes can adsorb “specifically” at the solid-solution interface [1,2]. To do this, a counterion must have a high enough “specific adsorption potential”. This is difficult to predict theoretically, and can best be studied is by electrokinetic titration.

In this work, we have performed electrokinetic titrations of a diverse group of pigmentary materials such as clays, TiO2 and silicates. Using this information, we have cationized TiO2 and measured the effect on its retention in paper. A Dynamic Handsheet Mold was used for this work. Kaolin clay was also cationized and used to prepare cationic paper coatings.