Origin of shear thickening in semidilute wormlike micellar solutions and evidence of elastic turbulence
- Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, U.P.A.L.M. C.P. 07738, Col. S. P. Zacatenco, Del. Gustavo A. Madero, Mexico D.F. (Mexico)
- Laboratorio de Reología y Física de la Matería Blanda, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, U.P.A.L.M. C.P. 07730, Col. S. P. Zacatenco, Del. Gustavo A. Madero, Mexico D.F. (Mexico)
- Departamento de Biotecnología, Centro de Desarrollo de Productos Bióticos, Instituto Politécnico Nacional, C.P. 62731, Col. San Isidro, Yautepec, Morelos (Mexico)
The origin of shear thickening in an equimolar semidilute wormlike micellar solution of cetylpyridinium chloride and sodium salicylate was investigated in this work by using Couette rheometry, flow visualization, and capillary Rheo-particle image velocimetry. The use of the combined methods allowed the discovery of gradient shear banding flow occurring from a critical shear stress and consisting of two main bands, one isotropic (transparent) of high viscosity and one structured (turbid) of low viscosity. Mechanical rheometry indicated macroscopic shear thinning behavior in the shear banding regime. However, local velocimetry showed that the turbid band increased its viscosity along with the shear stress, even though barely reached the value of the viscosity of the isotropic phase. This shear band is the precursor of shear induced structures that subsequently give rise to the average increase in viscosity or apparent shear thickening of the solution. Further increase in the shear stress promoted the growing of the turbid band across the flow region and led to destabilization of the shear banding flow independently of the type of rheometer used, as well as to vorticity banding in Couette flow. At last, vorticity banding disappeared and the flow developed elastic turbulence with chaotic dynamics.
- OSTI ID:
- 22360145
- Journal Information:
- Journal of Rheology, Vol. 58, Issue 6; Other Information: (c) 2014 The Society of Rheology; Country of input: International Atomic Energy Agency (IAEA); ISSN 0148-6055
- Country of Publication:
- United States
- Language:
- English
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