Microscopic Picture of Cooperative Processes in Restructuring Gel Networks

Abstract

Colloidal gel networks are disordered elastic solids that can form even in extremely dilute particle suspensions. With interaction strengths comparable to the thermal energy, their stress-bearing network can locally restructure via breaking and reforming interparticle bonds. This allows for yielding, self-healing, and adaptive mechanics under deformation. Designing such features requires controlling stress transmission through the complex structure of the gel and this is challenging because the link between local restructuring and overall response of the network is still missing. Here, we use a space resolved analysis of dynamical processes and numerical simulations of a model gel to gain insight into this link. We show that consequences of local bond breaking propagate along the gel network over distances larger than the average mesh size. This provides the missing microscopic explanation for why nonlocal constitutive relations are necessary to rationalize the nontrivial mechanical response of colloidal gels.

8 pages, 12 figures

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Cited by in corpus (5)

• Stress localization, stiffening and yielding in a model colloidal gel
• Microstructural rearrangements and their rheological implications in a model Thixotropic Elasto-Visco-Plastic (TEVP) fluid
• Self-assembly and cooperative dynamics of a model colloidal gel network
• Rheology of protein-stabilised emulsion gels envisioned as composite networks. 1 -- Comparison of pure droplet gels and protein gels
• Microscopic interactions and emerging elasticity in model soft particulate gels