The role of particle's surface on TiO2 performance

 
TiO2 pigments are typically 150 - 300 nm in size. However, they easily agglomerate in aqueous media, depending on pH and ionic strength. Agglomeration already occurs during calcination step. To achieve the best performance in final application (coatings, inks, plastic, paper, etc.) the particles should remain separated. For this purpose, processes such as dry grinding, dispersing, wet milling and surface treatment should be carried out under controlled conditions. Stabilization and surface modification of particles during the production of pigmentary TiO2 will be presented. To determine the stability of prepared TiO2 suspensions, z-potential and viscosity measurements were carried out. The resulting nanocoatings after inorganic surface treatment step were analyzed in terms of their surface morphology using electron microscopy. The influence of pigment quality on the performance in final applications was tested.