Interfacial response of a novel gemini metallo-surfactant to ionic guest species

The surface properties of a novel metallosurfactant with twin dodecyl aza-crown aliphatic tails (L3) were studied by surface pressure isotherms on aqueous subphases of selected Group I and Group II metals. Mean molecular areas of the headgroup at the monolayer interface (gas phase) are observed to decrease in response to aqueous phase complexation of L3 by metal ions in the order Ca2 +, Li+, Mg2 +, Na+, Ba2 + and K+. The surface-tension derived critical micelle concentration of L3 at 25 °C was 0.072 mM, while atomic force microscopy of aggregates observed after preparing Langmuir Blodgett multilayers on mica confirmed the formation of vesicles of up to 100 nm diameter as opposed to wormlike micelles formed by the monomeric analogs.