Rearrangement zone around a crack tip in a double self-assembled transient network Auteur(s): Foyart G., Ligoure C., Mora S., Ramos L. (Article) Publié: Acs Macro Letters, vol. 5 p.1080-1083 (2016) Texte intégral en Openaccess : Ref HAL: hal-01366306_v1 Ref Arxiv: 1607.02271 DOI: 10.1021/acsmacrolett.6b00516 WoS: 000385913800002 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 6 Citations Résumé: We investigate the nucleation and propagation of cracks in self-assembled viscoelastic fluids, which are made of surfactant micellesreversibly linked by telechelic polymers. The morphology of the micelles can be continuously tuned, from spherical to rodlike towormlike, thus producing transient double networks when the micelles are sufficiently long and entangled and transient singlenetworks otherwise. For a single network, we show that cracks nucleate when the sample deformation rate involved is comparable tothe relaxation time scale of the network. For a double network, by contrast, significant rearrangements of the micelles occuras a crack nucleates and propagates. We show that birefringence develops at the crack tip over a finite length, ξ, whichcorresponds to the length scale over which micelle alignment occurs. We find that ξ is larger for slower cracks, suggesting anincrease of ductility. |