Colloidal gels originate from solid objects with adhesive properties that are embedded in a fluid and self-assemble into a delicate percolating network. Despite their ubiquity in everyday products, ranging from food and cosmetics to building materials, our understanding of their gelation pathways and resulting mechanical response is limited. In this talk, we will demonstrate that the mechanical stability of these soft solids is governed by a phase transition known as the rigidity percolation transition. This transition reveals a new characteristic length scale, over which the bending modes held by colloidal strands dictate the mechanical properties. We will then present evidence that these findings are consistent across different preparation protocols, particle concentrations and types of interaction, providing valuable insights into how to adjust and control the elasticity of these intricate networks. Finally, I will briefly discuss the role played by strong adhesion in the gelation pathway and resulting elasticity.
Accès Salle des séminaires FAST-LPTMS (Bât. 530, salle C.120, 1er)