A first experimental step to understand the physics of shear-thickening suspensions
Cécile Clavaud
IUSTI, Marseille
Shear-thickening is an intriguing rheological behavior occurring in some suspensions. It consists in a brutal increase in the viscosity above a critical shear rate. The most famous example of such a behavior is that of a suspension of corn starch in water. A recent microscopic model explains this phenomenon as a frictional transition which arises from the presence of a repulsive force between the grains. In this talk, I will present experiments where we test the hypotheses of this model. In particular, we use a model system of silica beads in saline solutions, in which we can control the range of the repulsion. These experiments evidence the frictional transition, which we also link it to the shear-thickening behavior of the suspension.