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.
@article{arxiv.1203.0951,
title = {Structural Signature of a Brittle-to-Ductile Transition in Self-Assembled Networks},
author = {Laurence Ramos and Arnaud Laperrousaz and Philippe Dieudonne and Christian Ligoure},
journal= {arXiv preprint arXiv:1203.0951},
year = {2012}
}