Structural Signature of a Brittle-to-Ductile Transition in Self-Assembled Networks

Abstract

We study the nonlinear rheology of a novel class of transient networks, made of surfactant micelles of tunable morphology reversibly linked by block copolymers. We couple rheology and time-resolved structural measurements, using synchrotron radiation, to characterize the highly nonlinear viscoelastic regime. We propose the fluctuations of the degree of alignment of the micelles under shear as a probe to identify a fracture process. We show a clear signature of a brittle-to-ductile transition in transient gels, as the morphology of the micelles varies, and provide a parallel between the fracture of solids and the fracture under shear of viscoelastic fluids.

References in corpus (4)

• Solvent control of crack dynamics in a reversible hydrogel
• Shear-induced transitions and instabilities in surfactant wormlike micelles
• From Brittle to Ductile Fracture in Disordered Materials
• Structure factor of polymers interacting via a short range repulsive potential: application to hairy wormlike micelles

Cited by in corpus (8)

• Fractures in complex fluids: the case of transient networks
• A stress-controlled shear cell for small-angle light scattering and microscopy
• Fingering to fracturing transition in a transient gel
• Brittle fracture of polymer transient networks
• A novel setup coupling space-resolved dynamic light scattering and rheometetry unveils the heterogeneous flow field and non-affine dynamics in startup shear of a gel
• Continuum modelling of shear start-up in soft glassy materials
• Rearrangement zone around a crack tip in a double self-assembled transient network
• Instabilities in freely expanding sheets of associating viscoelastic fluids