VISCOSITY OF UNDECYLAMMONIUM CHLORIDE MICELLES IN AQUEOUS-SOLUTIONS OF SODIUM-CHLORIDE

Sodium chloride solutions of the surfactant undecylammonium chloride were subjected to viscosity and density measurements. The partial specific volume of the micelles increases with increasing ionic strength. The change of the intrinsic viscosity with the aggregation number or the ionic strength is small. The intrinsic viscosity value is close to that expected for spheroidal particles even when the aggregation number is as large as 974. The plots for dependence of the reduced viscosity on the concentration of micellized surfactant show downward curvature when the solvent is water or the ionic strength is relatively low. The large Huggins coefficient reflects interactions and/or micelle growth with increasing the surfactant concentration. Micelle-solvent and primary electroviscous effects seem to contribute very little to the intrinsic viscosity in our systems. © 1993 Academic Press, Inc.