Influence of colloidal interactions on pigment coating layer structure formation

The consolidation of pigment coating layers was simulated using a three-dimensional particle dynamics model. The model included hydrodynamic interactions as well as colloidal force models and the Brownian motion. The impact of various colloidal model parameters on the z-direction solids profile development and coating layer thickness was investigated. Also, the influence of continuous (liquid) phase viscosity was tested. Particle systems resembling a polydisperse ground calcium carbonate (GCC) distribution were studied. Results show that a lower particle surface potential on pigments increased the thickness of the coating layer, while the electrostatic double layer thickness influenced the internal coating structure. An increased viscosity of the continuous phase slowed the consolidation down, but did not have a significant impact on the final microstructure. The work contributes to the understanding of the influence of colloidal system properties on the consolidation and structure development of coating layers. The results may aid in the understanding of the impact of chemical additives on coating layer structure formation.