Aggregation behavior of anionic sulfonate gemini surfactants with dodecylphenyl tails

A series of anionic sulfonate gemini surfactants with the general structure [(C12H25)(C6H3SO3-)O(CH2)(m)O(C6H3SO3-)(C12H25)]2Na(+), designed as S, where m=2, 4, 6 and 8 denotes the number of carbon atoms in the oligomethylene spacer, was synthesized, and the surfactants' physicochemical properties and aggregation behavior were characterized. Compared with their single-tail analog, the gemini surfactants were observed to be more effective in decreasing the surface tension and their critical micelle concentrations (CMC) were at least two orders of magnitude lower. The aggregation process of the gemini surfactants in aqueous solution was investigated by dynamic light scattering (DLS). The formation of multivesicular structures consisting of several small vesicles surrounded by vesicular membrane was observed by cryogenic transmission electron microscopy (cryo-TEM). (C) 2015 Elsevier B.V. All rights reserved.