Scattering studies of mixed micelles formed from C₁₆TAB and C₁₂E₆ surfactants

Abstract

Scattering studies have been performed on a mixed micellar system containing a cationic surfactant C₁₆TAB (hexadecyl trimethylammonium bromide) and a non-ionic surfactant C₁₂E₆ (hexaethylene glycol monododecyl ether). Light-scattering measurements indicat ethat the addition of salt (KBr) initiates unidirectional growth of the mixed micelles into elongated aggregates. These elongated micelles exhibit some flexibility and can be characterised by scaling laws used to model polymer solutions. Small-angle neutron scattering (SANS) measurements indicate that the micelles usually prefer to exist as a single population of homogeneous aggregates, although evidence is obtained to suggest that some degree of de-mixing may occur in more dilute surfactant solutions containing salt.