Particle-Particle Interactions: The Link between Aggregate Properties and Rheology

Characteristic features of fine particle aggregates, such as aggregate sizes and densities, are strongly influenced by the detailed nature of the particle-particle interactions in that system. The features of these aggregates will, in turn, influence the properties of a settled bed of these aggregates, such as the shear yield strength and compressibility. Here, we discuss how measurements of individual particle-particle interactions, using techniques such as colloid probe microscopy, can be used to give detailed insights into the forces that control aggregate formation and breakup. We also review experimental measurement techniques that can be used for the detailed characterization of key aggregate properties: mean size, size distribution, and density. Finally, we show how links between these aggregate properties and the characteristic behavior of settled beds of particulates are made using direct measurements of bed properties such as shear and compressive yield strengths.