CONCENTRATION-DEPENDENCE OF THE MICELLE SIZE OF HEXAOXYETHYLENE GLYCOL DECYL ETHER AS REVEALED BY GEL-FILTRATION CHROMATOGRAPHY

Frontal gel filtration chromatograms (GFC) of hexaoxyethylene glycol decyl ether (C10E6) have been obtained with five kinds of gel, different in pore size, at 25°C. Among these gels, Sephadex G-10 with small pores gives the most easily analyzable data, since both small and large micelles are excluded from the pores. The concentration dependence of centroid volumes determined from GFC patterns is used to estimate monomer concentrations C1 of C10E6. Analysis of the concentration dependence of C1 by a multiple-equilibrium model for micelle formation provides micellar weight-average aggregation numbers nw as a function of total C10E6 concentration C. The nw value increases with an increase in C and is similar to that obtained from an analysis of Debye plots of light scattering data. Derivative GFC patterns also suggest the formation of small micelles at low concentrations. The utility of the GFC method in investigations of surfactants has been demonstrated. © 1990 American Chemical Society.