Rearrangement zone around a crack tip in a double self-assembled transient network

Abstract

We investigate the nucleation and propagation of cracks in self-assembled viscoelastic fluids, which are made of surfactant micelles reversibly linked by telechelic polymers. The morphology of the micelles can be continuously tuned, from spherical to rod-like to wormlike, thus producing transient double networks when the micelles are sufficiently long and entangled, and transient single networks otherwise. For a single network, we show that cracks nucleate when the sample deformation rate involved is comparable to the relaxation time scale of the network. For a double network, by contrast, significant rearrangements of the micelles occur as a crack nucleates and propagates. We show that birefringence develops at the crack tip over a finite length, $\xi$, which corresponds to the length scale over which micelles alignment occur. We find that $\xi$ is larger for slower cracks, suggesting an increase of ductility.

10 pages, 4 figures

References in corpus (4)

• Pattern Formation During Deformation of a Confined Viscoelastic Layer: From a Viscous Liquid to a Soft Elastic Solid
• Fractures in complex fluids: the case of transient networks
• Motion of a Viscoelastic Micellar Fluid Around a Cylinder: Flow and Fracture
• Structural Signature of a Brittle-to-Ductile Transition in Self-Assembled Networks

Cited by in corpus (1)

• Brittle fracture of polymer transient networks