Effect of surfactant concentration on the formation and viscoelasticity of anionic wormlike micelle by the methods of rheology and freeze-fracture TEM

Wormlike micelles and network structures were obtained for the samples with the anionic surfactant, sodium dodecyl trioxyethylene sulfate (SDES), and multivalent counterion electrolyte AlCl3 fixed in a proper concentration according to rheological measurements and the technique of freeze-fracture transmission electron microscopy (FF-TEM). The characteristics of a non-Newtonian fluid and the phenomenon of shear-induced structures transition were acquired from the steady-shear experiments. The TEM micrographs show the coexistence of wormlike micelles, entangled network structures, rod- and sphere- like micelles in the solutions. The Cole-Cole plot shows the rheological behavior of the non-linear viscoelasticity, the departure from the Maxwell model, and a relaxation time that is not simple. The plateau modulus G(0) and the relaxation time tau were also investigated to express the rheological properties of the wormlike micellar solutions.