Eur. Phys. J. B 6, 57-62 (1998)
https://doi.org/10.1007/s100510050526

Rheological behaviour and shear thickening exhibited by aqueous CTAB micellar solutions

Laboratoire de Physique des Liquides et des Interfaces, Groupe Rhéophysique des Colloïdes, Université de Metz, 1 boulevard F. Arago, 57078 Metz, France

Corresponding author: ^a cressely@lpli.sciences.univ-metz.fr

Received: 3 March 1998
Revised: 16 June 1998
Accepted: 3 July 1998
Published online: 15 November 1998

Abstract

In this experimental work we carefully investigate the rheological behaviour and in particular the shear thickening exhibited by aqueous micellar solutions of CTAB with NaSal as added counterion. We are particularly interested in the evolution of the critical shear rate (at which shear thickening occurs) versus C_D, the surfactant concentration. We show that , at fixed salt concentration C_S, increases with C_D following a power law evolution with a positive exponent of + 5.8. On the other hand we show that if the ratio is fixed, decreases with C_D with a negative exponent of -2.0. Nevertheless investigations of the zero shear viscosity indicate that in all situations (implying variation of the surfactant concentration C_D, or the salt concentration C_S or the temperature) is a decreasing function of the length of the micelles. All these evolutions are compatible with a gelation mechanism which could possibly be associated with entanglement effects of large interacting flowing structures.