On Relationships among the Aggregation Number, Rheological Property, and Turbulent Drag-Reducing Effect of Surfactant Solutions

In this study, turbulent drag-reducing effect, rheological characteristics and micelle aggregation number of aqueous solutions of anionic surfactant, sodium dodecyl sulfate (SDS), and cationic surfactant cetyltrimethylammonium chloride (CTAC) aided with sodium salicylate (NaSal). SDS solution was experimentally investigated at various concentrations in CMCs (critical micelle concentration) with and without sodium chloride. 200 ppm (ppm means part per million) CTAC/NaSal (mass ratio 1 : 1) solution was tested within temperature range from 20 degrees C to 80 degrees C. We were aiming at gaining insights into relationships among turbulent drag reduction rate, rheological properties and micelle microstructures of drag-reducing surfactant solution. Experiments on aggregation number, turbulent drag reduction and shear-rate dependent shear viscosity were performed for solution of SDS and 200 ppm CTAC/NaSal, respectively. The relationships among these three parameters were analyzed and discussed. The results are of importance from both theoretical and practical viewpoints for micellar transitions of surfactant solution.