Percolation in a Model Transient Network: Rheology and Dynamic Light Scattering Auteur(s): Michel Eric, Filali Mohammed, Aznar R., Porte Grégoire, Appell Jacqueline (Article) Publié: Langmuir, vol. 16 p.8702-8711 (2000) Texte intégral en Openaccess : Ref HAL: hal-00003062_v1 Ref Arxiv: cond-mat/0410278 DOI: 10.1021/la000317c WoS: 000165267300020 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 75 Citations Résumé: Step strain experiments and dynamic light scattering measurements are perfomed to characterize the dynamic behavior of an o/w droplet microemulsion into which is incorporated a telechelic polymer. At sufficient droplet and polymer concentrations, above the percolation threshold, the system is viscoelastic and its dynamic structure factor shows up two steps for the relaxation of concentration fluctuations: the fast one is dominated by the diffusion but the slower one is almost independent of the wave vector. The terminal time of the stress relaxation tR and the slow time of the dynamic structure factor tS are both presumably controlled by the residence time of a sticker in a droplet: consistently, tR and tS are of the same order, they both vanishes at the percolation threshold according to power laws but with different exponents. We discuss these features in terms of deviations at the transition, from the usual mean field description of the dynamics of transient networks. Commentaires: mars 2000 |