Rheological properties of cohesive soft materials using tailored functional microparticles – RHEOCOM

Powders, pastes and concentrated suspensions are ubiquitous in many geophysical and industrial applications. Their flow behavior is often very complex. The comprehensive understanding of their rheology implies to account for adhesive interactions as well as contact and friction interactions. For suspensions, hydrodynamic interactions come into play. When the adhesion is present, the bulk rigidity of the particles has also a strong role. The macroscopic behavior of a granular material or of a non-Brownian suspension is then strongly influenced both by the bulk rigidity and the surface interaction (adhesion, friction, roughness). The RHEOCOM project is a mainly experimental project, centered on the synthesis of solid particles arising from polymer emulsification. These particles will be then functionalized using the “click-chemistry” method to control the adhesion and long-distance interaction. Beyond the precise chemical and physical characterization of the particles, the macroscopic behavior of these functionalized particles will be investigated through well-known flow configurations. For granular materials made with these particles, flows down inclined plane or in rotating drums, small-scale rheology and compaction experiments are scheduled. For non-Brownian suspensions, rheology experiments and visualization of the micro-structure will be done. The outcomes of these experiments will feed theoretical models as well as numerical models, either for discrete or continuous simulations. The three partners of these RHEOCOM project (IMP Lyon, IUSTI Marseille et InPhyNi Nice) gather their skills to propose an unified approach of the rheology of complex systems, granular materials or non-Brownian suspensions.