On the nonlinear rheology of a wormlike micellar system in the presence of sodium salicylate salt

The nonlinear rheology of an aqueous wormlike micellar system made of cetyltrimethylammonium chloride with sodium salicylate is studied in this work. At high NaCl salt concentration the rheological measurements show a Maxwell behavior for all the solutions. The data of these samples are analyzed with respect to the Spenley, Cates, and McLeish model. The dimensionless quantities sigma(plateau)/G(0) and gamma c tau(R), which characterize the nonlinear rheology are compared to the predictions of this model. At a fixed surfactant concentration these quantities are found to be insensitive to changes in salt concentration and in temperature, respectively. The experimental value of the ratio sigma(plateau)/G(0) we find is close at hand to the theoretical one. A discrepancy between the theory and the experiments occurs,;however, in comparing the Weissenberg number defined by the product gamma c tau(R). (C) 1997 The Society of Rheology.