Shear-thickening in suspensions of deformable particles

Measurements of the shear thickening properties of various suspensions of deformable particles are discussed. The suspensions consist of small fraction wheat starch granules and agarose microgels in various hydrophilic media and show properties that are strongly dependent on the swelling behaviour of the particles. Results are compared with stokesian dynamics simulations of the flow of suspensions of spherical particles which include hydrodynamic interactions between particles and a model for a swollen polymer layer on the particle surface. This comparison confirms that the nature of the particle surface is crucial in determining the nature of the high shear behaviour of suspensions.