Rheologica Acta

, Volume 42, Issue 1, pp 56–63

Instabilities of micellar systems under homogeneous and non-homogeneous flow conditions

  • Arturo F. Méndez-Sánchez
  • M. Rosario López-González
  • V. Hugo Rolón-Garrido
  • José Pérez-González
  • Lourdes de Vargas
Original Contribution

DOI: 10.1007/s00397-002-0254-y

Cite this article as:
Méndez-Sánchez, A.F., López-González, M.R., Rolón-Garrido, V.H. et al. Rheol Acta (2003) 42: 56. doi:10.1007/s00397-002-0254-y

Abstract.

The rheological behavior of a cetylpyridinium chloride 100 mmol l–1/sodium salicylate 60 mmol l–1 aqueous solution was studied in this work under homogeneous (cone and plate) and non-homogeneous flow conditions (vane-bob and capillary rheometers), respectively. Instabilities consistent with non-monotonic flow curves were observed in all cases and the solution exhibited similar behavior under the different flow conditions. Hysteresis and the sigmoidal flow curve suggested as characteristic of systems that show constitutive instabilities were observed when running cycles of increasing and decreasing stress or shear rate, respectively. This information, together with a detailed determination of steady states at shear stresses close to the onset of the instabilities, allowed one to show unequivocally that "top and bottom jumping" are the mechanisms to trigger the instabilities in this micellar system. It is shown in addition that there is not a true plateau region in between the "top and bottom jumping". Finally, the flow behavior beyond the upturn seemed to be unstable and was found accompanied by an apparent violation of the no-slip boundary condition.

Keywords.

Micellar solutionsFlow instabilitiesTop and bottom jumpingSlipHomogeneous and non-homogeneous flow

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Arturo F. Méndez-Sánchez
    • 1
    • 2
  • M. Rosario López-González
    • 1
  • V. Hugo Rolón-Garrido
    • 1
  • José Pérez-González
    • 1
  • Lourdes de Vargas
    • 1
  1. 1.Laboratorio de Reología, Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Apdo. Postal 75–685, C. P. 07300, México, D. F., México
  2. 2.Metalurgia y Materiales, Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, México, D. F., México