Toughness of Double Network Hydrogels: The Role of Reduced Stress Propagation
Year: 2025
Type: article
Abstract: Double network hydrogels show remarkable mechanical performance, combining high strength and fracture toughness with sufficient stiffness to bear load, despite containing only a low density of cross-linked polymer molecules in water. We introduce a simple mesoscale model of a double network material, detailed enough to resolve the salient microphysics of local plastic bond breakage, yet simple enough to address macroscopic cracking. Load sharing between the networks results in a delocalization of stress such that the double network inherits both the stiffness of its stiff-and-brittle sacrificial network and the ductility of its soft-and-ductile matrix network. The underlying mechanism is a reduction in the Eshelby stress propagator between sacrificial bonds, inhibiting the tendency for the plastic failure of one sacrificial bond to propagate stress to neighboring sacrificial bonds and cause a follow-on cascade of breakages. The mechanism of brittle macroscopic cracking is thereby suppressed, giving instead ductile deformation via diffusely distributed microcracking.
Source: Physical Review Letters
DOI: 10.1103/kck9-tc46
Authors: Samuel B. Walker, Suzanne M. Fielding
Institution: Durham University
Language: English
Subfield: Molecular Medicine
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Award: G4478540802
OpenAlex ID: W4415719875