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(254) Production(s) de RAMOS L.
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Structure of a new type of transient network : entangled wormilike micelles bridged by telechelic polymers
Auteur(s): Ramos L., Ligoure C.
(Article) Publié:
Macromolecules, vol. 40 p.1248-1251 (2007)
Ref HAL: hal-00502754_v1
DOI: 10.1021/ma0621167
WoS: 000244160800065
Exporter : BibTex | endNote
49 Citations
Résumé: The thermodynamics and structural behavior of a new type of transient network are reported. The network is obtained by adding in a solution of entangled surfactant wormlike micelles a telechelic triblock copolymer whose hydrophobic ends anchor into the micelles and whose hydrophilic tails are swollen in the aqueous solvent and reversibly link the entangled cylindrical micelles. For comparison, we have also studied the same surfactant system decorated with an amphiphilic diblock copolymer which corresponds exactly to a triblock telechelic copolymer cut into two identical diblock copolymers. We find that the addition of telechelic polymers induces an effective attraction of entropic origin between the surfactant that may result, in equilibrium, in the coexistence of a dilute phase and a connected network, as predicted by theory. Small-angle neutron scattering experiments show first that the locally cylindrical structure of the micelles is maintained upon copolymer addition over a wide range of copolymer-to-surfactant molar ratio. On the other hand, the addition of telechelic polymer correlates with (i) the emergence of a broad peak in the structure factor at a finite scattering vector, q, due to the short-range steric repulsion induced by the polymer between the cylinders, and (ii) the large rise of the scattered intensity at low q's (for small enough surfactant concentration), which indicates an increase of the osmotic compressibility of the solution due to the effective attractive interaction between cylinders provoked by the telechelic polymers linking them.
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Role of the preparation procedure in the formation of spherical and monodisperse surfactant/polyelectrolyte complexes
Auteur(s): Luan Y., Ramos L.
(Article) Publié:
Chemistry - A European Journal, vol. 13 p.6108-6114 (2007)
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Real-time observation of polyelectrolyte-induced binding of charged bilayers
Auteur(s): Luan Y., Ramos L.
(Article) Publié:
Journal Of The American Chemical Society, vol. 129 p.14619-14624 (2007)
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Origin of the slow dynamics and the aging of a soft glass
Auteur(s): Ramos L.
Conference: 81 st ACS Colloid & Surface Science Symposium (Newark, USA, FR, 2007-06-24)
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Origin of the Slow Dynamics and the Agin of a Soft Glass
Auteur(s): Ramos L.
Conference: Universal Aspects in Soft Matter : Slow Dynamics Topical Meeting of the Network of Excellence SoftComp (San Sebastian, Spain, FR, 2007-12-12)
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Dynamique spontanée et sous contrainte de systèmes encombrés
Auteur(s): Ramos L.
Conference: Mini colloque rhéologie (Montpellier, France, FR, 2007-10-08)
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Collective rearrangement at the onset of flow of a polycrystalline hexagonal columnar phase
Auteur(s): Ramos L.
Conference: 4 th Annual European Rheology Conference (Naples, Italy, FR, 2007-04-11)
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