A Relation between Solubilizatioii Capacity and Zeta-Potential for the Micelles of a Series of Dodecylpolyoxyethylene Sulfates

Abstract

Solubilization behaviors of sodium dodecylpolyoxyethylene sulfates (SDPS) with oxyethylene units (p) from 0 to 10 in the presence of added salts have been studied in connection with the zeta-potentials of the micelles. Solubilizing power of SDPS for Yellow-OB increases with increasing p and, at a definite value of p, it increases with decreasing zeta-potential or effective charge of the micelle. The presence of calcium chloride lowers the zeta-potential more effectively than that of sodium chloride, and consequently increases the solubilizing power more effectively. From these results, the relation between the solubilizing behavior and the electrical nature of the micelles has been discussed by taking into account the structure of the micelles.