Micelle formation in aqueous solutions of dodecylbenzene sulfonic acid studied by small-angle neutron scattering

Structure and interaction parameters of micelles in solutions of dodecylbenzene sulfonic acid (DBSA) in deuterated water are studied by small-angle neutron scattering. The dependences of micellar aggregation number, fractional charge, charge per micelle and surface potential on surfactant concentration are analyzed. A typical increase in the micelle size with the growth in the acid content is found, which can be related to the transition from spherical to rod-like micelles. The obtained data are used for estimating surfactant micelle concentration in water-based ferrofluids stabilized with DBSA.