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(119) Production(s) de LIGOURE C.
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Fracture fragile versus fracture fluide dans les fluides complexes: le paradigme experimental des réseaux transitoires auto-assemblés
Auteur(s): Ligoure C.
(Séminaires)
Séminaire général du département de physique de l'ENS (Paris, FR), 2009-07-03 |
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Nonlinear Rheology of Surfactant Wormlike Micelles Bridged by Telechelic Polymers 
Auteur(s): Tabuteau Hervé, Ramos L., Nakaya-Yaegashi Kaori, Imai Masayuki, Ligoure C.
(Article) Publié:
Langmuir, vol. 25 p.2467-2472 (2009)
Ref HAL: hal-00514229_v1
PMID 19199743
DOI: 10.1021/la803304z
WoS: 000263373600083
Exporter : BibTex | endNote
20 Citations
Résumé: We have investigated the nonlinear rheology of a soft composite transient network made of a solution of surfactant wormlike micelles (WM) in the semidilute regime that are reversibly bridged by telechelic polymers. The samples are well described, in the linear regime, as two Maxwell fluids components blends, characterized by two markedly different characteristic times. The slow mode is mainly related to the transient network of entangled WM, and the fast mode to the network of telechelic chains. In this paper we investigate the nonlinear viscoelasticity and show that the nonlinear behavior reflects as well the behavior of two coupled networks. On one hand, stress relaxation experiments and time-resolved stress response following the application of a constant shear rate show that, in the weakly nonlinear regime, these novel composite networks stiffen. A fourfold increase of the elastic modulus with respect to the linear value is reached for strain amplitude of about 200%. This strain hardening is due to the nonlinear stretching of the telechelic polymer chains. On the other hand, the samples exhibit shear banding in the highly nonlinear regime, similarly to pure semidilute solutions of WM.
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Microscopic Mechanisms of the Brittleness of Viscoelastic Fluids
Auteur(s): Tabuteau Hervé, Mora S., Porte Grégoire, Abkarian M., Ligoure C.
(Article) Publié:
Physical Review Letters, vol. 102 p.155501 (2009)
Ref HAL: hal-00503271_v1
PMID 19518646
DOI: 10.1103/PhysRevLett.102.155501
WoS: 000265285700042
Exporter : BibTex | endNote
61 Citations
Résumé: We show that a large class of viscoelastic fluids, i.e., transient networks, are brittle according to the Griffith's theory of solid fracture. However, contrary to solids, cracks are intrinsic to the material arising from the equilibrium nature of the fluid microstructure. The brittleness of these fluids comes from thermal fluctuations of bonds distribution. In this approach, the rupture stress is predicted to be on the order of the Young modulus, in very good agreement with experimental values.
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Entangled Worm-like Micelles Bridged by Telechelic Polymers: A Model of Soft Composite Transient Networks
Auteur(s): Ligoure C.
Conférence invité: Engeenering conferences Inernational : Association in Solution II, (Tomar, PT, 2009-07-26)
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Self-assembled networks. A paradigm to investigate the concepts of brittleness and ductility in complex fluids
Auteur(s): Ligoure C.
Conférence invité: Plenary annual meeting of the Europena network of excellence SOFTCOMP (Venise, IT, 2009-05-04)
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Ductility versus Brittleness in Self-Assembled Transient Networks
Auteur(s): Tabuteau Hervé, Mora S., Ramos L., Porte Grégoire, Ligoure C.
Conference: International Symposium on Non-Equilibrium Soft Matter (Kyoto, JP, 2008-06-02)
Actes de conférence: PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, vol. p.47-53 (2008)
Ref HAL: hal-00503273_v1
Exporter : BibTex | endNote
Résumé: We show that two types of complex fluids belonging to the same class of soft materials (transient networks), and having the same linear rheological properties (Maxwell fluids) exhibit two distinct fracture behaviors as solids do. We have designed a third experimental system that captures the distinct features of both former ones. We show that it could be a good candidate to investigate the brittle-ductile transition in complex fluids.
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