Abstract
Conductivity measurements are presented in two isotropic micellar solutions and in the nematic phase of the sodium salicylate/cetylpyridimium chloride/H2O system under shear. For the isotropic solutions the concentrations studied correspond to the plateau behaviour in the flow curve for this system. The measured anisotropy in the shear-aligned isotropic solutions is at least one order of magnitude smaller than the anisotropy in the nematic phase. Time-resolved measurements show that the relaxation behaviour on shear start-up and on shear cessation is much faster in the isotropic solutions than in the nematic phase. The results suggest that the micelles in the shear-induced low viscosity phase are shorter than in the nematic phase.
Acknowledgements
The continued presence of Alfred Saupe is gratefully acknowledged, together with his enrichment of the author's professional, personal and spiritual life.