How rigidity percolation and bending stiffness shape particle network elasticity
| When |
Mar 26, 2026
from 11:00 to 12:00 |
|---|---|
| Where | MGN1 107 |
| Attendees |
David Richard |
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Colloidal gels form when small solid particles suspended in a liquid stick to one another and spontaneously assemble into a tenuous, space-spanning network. These soft solids are ubiquitous in everyday materials from foods and cosmetics to paints and construction products, yet the processes that lead to their formation and determine their mechanical properties remain only partially understood. In this talk, I will show that the mechanical stability of colloidal gels is controlled by a phase transition known as the rigidity percolation transition. At this transition, the network first becomes mechanically stable, revealing a characteristic length scale over which bending deformations of the particle strands dominate the material’s response. We will present evidence that this framework consistently describes gels formed under a wide range of preparation protocols, particle concentrations, and interaction types. These results provide insight into how the elasticity of colloidal gels can be tuned and controlled. In the second part of the talk, I will discuss how strong interparticle adhesion influences both the gelation pathway and the resulting elastic properties of the network.