Non-linear mechanics and rheology of dense suspensions: nanoscale structure to macroscopic behavior

Coordinators: Emanuela del Gado, Jeff Morris, Peter Olmsted and Wilson Poon

Flow of dense suspensions is at the core of industrial technologies for cements and pastes, drilling and recovery, personal care and chemical products, slurry and powders. The flow-property transitions of these suspensions, much like classical phase behavior in material physics, have enormous practical relevance, as they determine the processing conditions for a material in engineering contexts. The key question is how interactions between microscopic constituents give rise to a macroscopic transition, while the specific transition strongly depends upon the external forcing. The development of a statistical mechanics framework is crucial for a quantitative understanding of a wide range of mechanical instabilities that arise when the solid volume fraction is high and the deformation rate change, from the shear banding associated with yielding to discontinuous shear thickening.

The conference will bring together statistical physicists, material scientists, engineers and mathematicians to discuss the rheological behavior of dense suspensions in contexts (flow geometries, deformation rates) relevant to technological applications of materials ranging from compressed emulsions to colloids and grains; the nanoscale and microscale origin of such rheology; the development of constitutive models able to capture non-linearities, leading to non-monotonic flow curves and able to bridge the nanoscale physics to the mechanics and flow properties, and ultimately to the macroscopic engineering problems.