SOME MICELLAR PROPERTIES OF STRAIGHT-CHAIN SODIUM ALKYLBENZENE SULFONATES

Measurements of viscosities, densities, sedimentation and diffusion coefficients have been made of the micellar solutions of a series of straight-chain sodium alkylbenzene sulfonates, CnH2 n+1C6H4SO3Na with n from 10 to 15. For the lower members of the surfactants, with n=10 and 12, the effects of the position of phenyl group on the micellar proporties were examined. It is estimated from the above hydrodynamic data that the micelles of the lower members are small, spherical and highly hydrated while those of the higher members are comparatively large and asymmetric. The micellar properties of the lower members are dependent on their phenyl position. In addition, the electrophoretic mobilities of the micelles were measured to obtain the ζ-potential of the micelles and to learn their electrochemical behaviors. © 1968 Dr. Dietrich Steinkopff Verlag.