THEORY OF SEDIMENTATION IN COLLOIDAL SUSPENSIONS

Theoretical models of sedimentation and creaming in colloidal dispersions and emulsions need to account for effects such as particle interactions as well as sediment consolidation. Traditional theories, such as that of Kynch, are based on continuum pictures of the system but ignore some effects which arise from the particulate nature of the dispersion, e.g. excluded volume effects. We have made a numerical investigation of the continuum model, based on analytic solutions of Burger's equation, which highlights the role of interactions in controlling sedimentation rates and which indicates the range of validity for solitary wave models. As an example of particulate effects we have illustrated the consequences of shaking on the compaction and size segregation of sediments composed of binary disk mixtures in two dimensions. © 1990.