Role of counterion distribution on the structure of micelles in aqueous salt solutions: small-angle neutron scattering study

Small-angle neutron scattering studies have been carried out on aqueous micellar solutions of cationic surfactant cetyltrimethylammonium bromide (CTAB) at different temperatures in presence of varying concentration of salt KBr. It is found that the micelles grow strongly with the addition of salt at low temperatures and this effect is significantly reduced with the increase in the temperature. These results are explained in terms of excess of counterions around the micelles with the increase in the temperature.