LIGHT-SCATTERING STUDY ON THE MICELLAR SYSTEMS SOLUBILIZING A FATTY-ACID

The effect of oleic acid on the aggregational behavior of the alpha-su lfonated fatty acid methyl ester sodium salt (alpha-SFMe) and sodium l inear C-12/C-14-alkylbenzene-sulfonate (LAS) has been studied using a light-scattering method. The solubilizing capacity of alpha-SFMe was l arger than that of LAS, and depended both on the number of micelles in the surfactant solution and the solubilized amount per micelle. When the micellar weights for the alpha-SFMe and LAS systems were determine d at the various oleic acid/surfactant ratios, the micellar weights in itially decreased by small amounts of solubilizate and then increased with the further increase in the solubilized amounts. It was found tha t the solubilization process is accompanied by a reconstitution of the micelles.