Rheological behavior of an elongated micellar solution at low and high salt concentrations

The aim of this experimental work is to investigate the mechanism responsible of the decrease of the zero shear viscosity at high inorganic salt content. We report the linear and some nonlinear rheological properties of aqueous worm-like micellar solutions of CTAB containing NaNO3 salt. The zero-shear viscosity eta(0) curve versus salt concentration exhibits a well-defined maximum. We choose two salt concentrations (low and high) having the same zero-shear viscosity, carefully explore the rheological characteristics and their evolutions in (and around) these two situations. The experimental results presented here, without excluding the possibility of the connections, suggest the possibility that the decreasing of eta(0) is a result of the reduction in size of the worm-like micelles.