Engineering Soft Jammed Materials

The production of many commercial products involves highly concentrated dispersions of particles in water. These materials are designed to behave like soft elastic solids at rest but to yield and flow at large stresses. The solid-liquid transition is associated with unique rheological properties which depend on the jammed structure of the materials, on the particle architecture and on specific interactions due to contact forces.

We will focus on the important class of soft materials which made of deformable colloidal particles: emulsions, microgels, multilamellar vesicles, star polymers and copolymer micelles. A micromechanical model connects the local scale properties to the macroscopic behaviour and predicts near-equilibrium properties (statistical distribution, osmotic pressure, shear modulus), non linear rheology (shear and normal stresses), slip and other surface phenomena observed near smooth surfaces. The results highlight the universality of the flow properties of soft jammed materials and provide predictive tools for designing specific products