Structure formation mechanisms in consolidating pigment coatings - Simulation and visualisation

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Anders Sand, Jani Kniivilä, Martti Toivakka, Tuomo Hjelt
Publisher: ELSEVIER SCIENCE SA
Publication year: 2011
Journal: Chemical Engineering and Processing
Journal acronym: CHEM ENG PROCESS
Volume number: 50
Issue number: 5-6
Start page: 574
End page: 582
Number of pages: 9
ISSN: 0255-2701


Abstract

Microstructure development in consolidating pigment coating layers was studied in terms of particle flocculation and clustering mechanisms utilising a 3D particle dynamics model. The model includes hydrodynamic forces, colloidal interactions as well as the Brownian motion. The influence of colloidal interactions and drying strategy on the coating layer thickness development and internal solid concentration gradients, was investigated. A low particle surface potential resulted in the formation of porous particle networks, which impeded the shrinkage of the coating layer. At higher surface potentials particles arranged into denser structures, whereby the solids concentration profile could be controlled by the drying. Low electrostatic double layer thicknesses allowed sharp concentration gradients to form as result of the applied drying strategy. At high double layer thicknesses, the structure formation was similar regardless of drying strategy. This work elucidates the combined effect of drying conditions and colloidal suspension properties on coating microstructure development. Furthermore, the results aid in the understanding of how coating suspension additives may influence the structure development of the coating layer.


Keywords

Clustering, Colloidal interactions, Consolidation, Drying, Dynamics, Pigment coating

Last updated on 2020-02-04 at 03:17