Results that stick: how adhesive particle properties affect their collective flow behavior

Interparticle forces are very relevant for granular flow dynamics. Here we experimentally probe whether adhesive characteristics of particles also affect the rheology of such particle suspensions. We used ceramic microparticles with a size distribution between 10-100 micrometer; these particles are base materials for porcelain stoneware. We characterize particle adhesion forces by using colloid probe atomic force spectroscopy. We find that acidic and basic environments can induce an increase in the adhesion capacity of certain types of ceramic particles. Additionally, the adhesion force can be contact time and retraction speed dependent; results repeat over many cycles. We attribute the adhesion dynamics to the presence of clay inside the ceramic microparticles. The adhesive properties of the ceramic microparticles also may affect their collective behavior in suspension, as we confirm that the rheology of ceramic microparticle suspensions is strongly pH dependent. Our results suggest that adhesive particle properties are relevant to consider in the analysis of suspension dynamics.