TEMPERATURE AND FLOW-INDUCED VISCOSITY TRANSITIONS FOR CTAB SURFACTANT SOLUTIONS

We report in this work new results concerning the temperature dependen ce of the non-Newtonian viscosity of semi-diluted aqueous micellar sol utions of cetyltrimethylammonium bromide (CTAB) in the presence of pot assium bromide (KBr). Two structural transitions are responsible for t he unusual flow curves obtained. The first transition induced by the s hear flow corresponds to an induced liquid crystalline phase of the ne matic type; the second corresponds to the disappearing of this phase w ith increase of the temperature.