No abstract

No abstract

No abstract

In this experimental work we investigate the effect of the addition of simple salts such as NaNO3, NaBr, NaCl, NaF on the rheological behaviour of an aqueous micellar solution of CTAB 0.1 M with NaSal at the concentration of 0.019 M. Experimental results indicate that the rheological characteristics of the solution CTAB/NaSal exhibiting shear thickening (critical shear rate corresponding to the occurrence of the shear-induced structure, amplitude of the phenomenon, slope corresponding to the shear thinning evolution following the maximum viscosity) are progressively, but differently affected by the addition of the inorganic salts. The effect of only a simple screening of electrostatic interactions is shown by the addition of small amounts of NaF.

V. Hartmann ) Prof. R. Cressely ( ) Laboratoire de Physique des Liquides et des interfaces Groupe Rhe´ophysique des Colloides Universite´de Metz -1Bd F. AragoAbstract In this experimental work we carefully investigate the influence of some organic counterions (having similarities): sodium salicylate (NaSal), sodium tosylate (NaTos) and sodium benzoate (NaBz) on the rheological properties of two aqueous solutions (0.1 and 0.05 M) of cetyltrimethylammonium bromide (CTAB). Here we are particularly interested in the occurrence of the shear thickening effect corresponding to shear induced structures (SIS). All the rheological measurements presented in this work are realized with the same geometrical device (plan-cone) with controlled imposed shear stress. Conditions of occurrence and evolutions of the characteristics of the obtained shear thickening are given.