Resumo

ROLON-GARRIDO, V.H.; PEREZ-GONZALEZ, J.  e  VEGA ACOSTA MONTALBAN, L.A.. Vane rheometry of an aqueous solution of worm-like micelles. Rev. mex. fis. [online]. 2003, vol.49, n.1, pp.40-44. ISSN 0035-001X.

The non-linear viscoelastic behavior of worm-like micelles in aqueous solution was analyzed in this work under non-homogeneous flow with a rotational vane rheometer. The system studied was a solution of cetylpyridinium chloride 100 mM/sodium salicylate 60 mM (CPyCl/NaSal) in triple distilled water. The use of the vane rheometer enables to reach higher shear rates than a cone and plate or Couette one because ejection of the sample and slip at the rotating surface are restricted. Thus, following this experimental procedure we show in this work, the complete flow curve for a micellar solution, including a hysteresis cycle and the upturn at high shear rates predicted by theories on constitutive instabilities and shear banded flow. We show in addition, the influence of time on the onset of flow instabilities and an experimental analysis of the flow stability in the low and high shear rate branches.

Palavras-chave : Vane rheometry; micellar solutions; flow instabilities; top and bottom jumping.

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