Reti di fibre colloidali sotto sforzo : deformazione di taglio e carico gravitazionale

We describe our investigation of the yield behavior of a network of hydrophobic fibers in an aqueous surfactant solution, when submitted either to a macroscopic shear stress or to the gravitational load of density-mismatched particles. In both cases, the gel undergoes an initial, slow deformation followed by delayed yielding or respectively collapse. However, the time scales for the yielding process strongly differ from each other both on an absolute scale and in their dependence on the effective stress applied. We discuss the analogies, the differences and the interplay between these destabilization modes.