Structural and Transport Properties of Bola C-16 Micelles in Water and in Aqueous Electrolyte Solutions

Aqueous solutions containing a bolaform surfactant [R,ω-(4,7,10,13-pentaoxa-16-azacyclooctadecane)- hexadecane], with and without electrolytes have been investigated as a function of surfactant concentration and ionic strength. Small angle neutron scattering (SANS), NMR self-diffusion, and other physical-chemical methods were used. From the analysis of SANS data it was inferred that in water the surfactant forms slightly charged ellipsoidal micelles, because of the partial hydrolysis of amino groups. The aggregates grow with the increase of concentration, becoming more elongated. Due to the selective complexing ability of aza crown ether units, significant differences were observed upon add…