Journal of Rheology, Vol.64, No.4, 879-888, 2020
Linear wormlike micelles behave similarly to entangled linear polymers in fast shear flows
We report shear startup data on solutions of entangled linear wormlike micelles, only differing in the concentration of a binding aromatic salt. Wormlike micelles behave similarly to ordinary polymers in fast shear flows, exhibiting pronounced overshoots as well as tiny undershoots in transient shear viscosity, before approaching the steady state. The analogy is here emphasized by successfully comparing data with predictions of a constitutive equation recently adopted for ordinary entangled polymers. In the fast shear flow, entangled linear wormlike micelles appear to align, stretch, and tumble just like polymeric chains.