Cohesivity and Colloidal Properties Affecting the Dispersibility of Ni/Sb‐Doped TiO2 Powders

The colloidal properties and cohesivity of Ni/SB‐doped TiO2 powders (normal sizes ranging from 0.7–1.3 (μm) have been studied. Pretreatment of the powders via washing proved to be necessary in order to obtain consistent and reproducible aqueous suspension behavior. The point‐of‐zero‐charge of the powders was found to range from pH 5.8‐7.8 from measurements of the sedimentation volume and particle size analyses performed for dispersions prepared at various pH values. Surface and mass titration studies corroborated these results. Stability characterization studied in nonaqueous solvents revealed the partial solubility parameters for the powders as well as the usefulness of drying the powder for the preparation of stable nonaqueous dispersions. In addition, tensile strength measurements revealed that drying the powders reduces their cohesivity. These results are useful for determining favorable processing strategies and optimal conditions for dispersibility in coatings formulations.