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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 26: Biomaterials and Biopolymers (joint session BP/CPP)

CPP 26.5: Vortrag

Mittwoch, 20. März 2024, 10:45–11:00, H 1028

Strain-Controlled Critical Slowing Down in the Rheology of Disordered Networks — •Abhinav Sharma^1,2, Jordan Shivers³, and Fred MacKintosh³ — ¹Mathematisch-Naturwissenschaftlich-Technische Fakultät, Universität Augsburg, 86159 Augsburg — ²Leibniz Institute für Polymerforschung, Dresden — ³Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, USA

Networks and dense suspensions frequently reside near a boundary between soft (or fluidlike) and rigid (or solidlike) regimes. Transitions between these regimes can be driven by changes in structure, density, or applied stress or strain. In general, near the onset or loss of rigidity in these systems, dissipation-limiting heterogeneous nonaffine rearrangements dominate the macroscopic viscoelastic response, giving rise to diverging relaxation times and power-law rheology. Here, we describe a simple quantitative relationship between nonaffinity and the excess viscosity. We test this nonaffinity-viscosity relationship computation- ally and demonstrate its rheological consequences in simulations of strained filament networks and dense suspensions. We also predict critical signatures in the rheology of semiflexible and stiff biopolymer networks near the strain stiffening transition.

Keywords: Biopolymers; Rheology; Criticality; Nonaffine