Topological Origins of Yielding in Colloidal Gels

Yielding of colloidal gels under applied deformation is accompanied by various microstructural changes in the particulate network including rearrangement, bond rupture, anisotropy, and reformation of secondary structures. While much work has been done to understand the physical underpinnings of yielding in colloidal gels, its topological origins remain poorly understood. The question of which bonds/particles are primarily prone to these break-up events and ultimately responsible for the yielding of a gel remains unanswered. Here, we seek to understand the bond characteristics that correlate with break-up events and provide a topological origin to the yielding mechanism in colloidal gels. Here, employing a series of large-scale dynamic simulations and network science tools, we characterize the bonds using their orientation and network centrality. We find that bonds with higher centralities in the network are ruptured the most at all applied deformation rates. This suggests that a network analysis of the particulate structure can be used to predict the failure points in colloidal gels a priori.