The Study of Surfactant-Alcohol Mixed Micelles Using Conductance, Viscosity, and Electromotive Force Measurements

Publisher Website
Google Scholar
Abstract
Conductance, viscosity, and EMF measurements were used to characterize solutions containing surfactant-alcohol micelles. The materials studied included sodium dodecyl sulfate (SDS), sodium octyl sulfate (SOS), decyltrimethylammonium bromide (DTAB), hexadecyltrimethylammonium bromide (CTAB) and the alcohols 1-pentanol through 1-octanol. The addition of alcohols caused the conductance of a 2% SDS solution to increase, and of a 3% solution of DTAB and of a 7% solution of SOS to decrease. CTAB showed both increases and decreases upon addition of alcohol. The EMF measurements permitted the concentration of free surfactant monomer and of unbound counterion in equilibrium with the micelle to be determined. When combined with the viscosity data, the change in conductance upon addition of alcohol can be interpreted in terms of changes in micellar shape and in the concentration of involved ions.