Linear viscoelasticity of entangled wormlike micelles bridged by telechelic polymers : an experimental model for a double transient networkReport as inadecuate




Linear viscoelasticity of entangled wormlike micelles bridged by telechelic polymers : an experimental model for a double transient network - Download this document for free, or read online. Document in PDF available to download.

* Corresponding author 1 LCVN - Laboratoire des colloïdes, verres et nanomatériaux 2 Department of Physics,

Abstract : We survey the linear viscoelasticity of a new type of transient network: bridged wormlike micelles, whose structure has been characterized recently Ramos and Ligoure, 2007. This composite material is obtained by adding telechelic copolymers water-soluble chains with hydrophobic stickers at each extremity to a solution of entangled wormlike micelles WM. For comparison, naked WM and WM decorated by amphiphilic copolymers are also investigated. While these latter systems exhibit almost a same single ideal Maxwell behavior, solutions of bridged WM can be described as two Maxwell fluids components blends, characterized by two markedly different characteristic times, t fast and t slow, and two elastic moduli, G fast and G slow, with G fast >> G slow. We show that the slow mode is related to the viscoelasticity of the transient network of entangled WM, and the fast mode to the network of telechelic active chains i.e. chains that do not form loops but bridge two micelles. The dependence of the viscoelasticity with the surfactant concentration, phi, and the sticker-to-surfactant molar ratio, beta, is discussed. In particular, we show that G fast is proportional to the number of active chains in the material, phi beta. Simple theoretical expectations allow then to evaluate the bridges-loops ratio for the telechelic polymers.

Keywords : wormlike micelles telechelic polymer transient network viscoelasticity





Author: Kaori Nakaya - Laurence Ramos - Herve Tabuteau - Christian Ligoure -

Source: https://hal.archives-ouvertes.fr/



DOWNLOAD PDF




Related documents