The Effects Of Surface And Particle Properties On Van Der Waals (Vdw) Adhesion Quantified By The Enhanced Centrifuge Method

The topographical features on the individual particles in a powder and the surfaces with which they interact affect the powder adhesion. An experimental and modelling framework called the Enhanced Centrifuge Method (ECM) maps particle and surface properties onto 'effective' Hamaker constant distributions that describe the van der Waals (vdW) adhesion between a powder and a surface. The ECM was used to study the adhesion between polystyrene powder and silica surfaces to exemplify the 'effective' Hamaker constants quantify the effects of particle and surface properties on adhesion. Silica surfaces were polished to alter their surface roughness profiles to reveal levels of roughness in which the adhesion was controlled by either the powder or surface properties. This study revealed surface roughness height descriptions are inadequate descriptors of adhesion, and instead the frequency of roughness peaks to the particle size must be considered. This result was verified using an existing particle adhesion simulator. (c) 2021 Elsevier B.V. All rights reserved.