SHEAR HISTORY EFFECT ON A PHASE-TRANSITION UNDER SHEAR OF A SALT-FREECTAB SOLUTION

We present the results of theological measurements showing the evoluti on of shifting Nematic/Isotropic temperature transition under shear. N ematic phase is induced from shear and disappears when temperature ris es (always under shear). Successive temperature sweeps on the same sol ution have a significative effect on the transition temperature showin g thus a kind of memory effect. The micellar system studied here is ca tionic (CTAB) without salt added at concentration of 0.6 M/1 which is near but inferior to the concentration leading to the formation of an hexagonal phase at rest.