SODIUM DODECYL-SULFATE INDUCED ENHANCEMENT OF THE VISCOSITY AND VISCOELASTICITY OF AQUEOUS-SOLUTIONS OF POLY(ETHYLENE OXIDE) - A RHEOLOGICAL STUDY ON POLYMER MICELLE INTERACTION

A large enhancement of the viscosity and the viscoelasticity of aqueous solutions of high molecular weight poly(ethylene oxide) (PEO) has been observed upon addition of sodium dodecyl sulfate (SDS). The changes in apparent viscosity, in the parameters for the power law model of non-Newtonian behavior, and in the viscoelasticity start at the critical concentration for formation of polymer-bound micelles and level off above the saturation concentration. These phenomena are attributed to coil expansion of PEO induced by binding of SDS micelles onto the polymer. At high SDS concentration and high shear rate, the normal stress difference, which is a measure of the viscoelasticity, becomes almost independent of shear rate. This peculiar behavior is proposed to arise from partial shear-induced breakdown of the polymer-micelle complexes.