Ecole des Ponts - Peking University joint workshop Rheology of complex fluids: modeling and numerics. List of abstracts

While many fluid instabilities involving free surfaces are governed by interfacial forces the classic example being surface tension real materials often have surface forces produced by physical processes not present in the bulk. A striking example of this is a viscoelastic micellar fluid, in which the long tubelike aggregates form at low concentrations due to the presence of an organic salt/cosurfactant, without which the micelles are spherical and the fluid is completely Newtonian. I will present some of our recent experimental observations and modeling of the instabilities occurring when two such Newtonian fluids react to produce a fragile elastic micellar material, either during impact splashes or viscous fingering.