Gemini surfactants critical micelle concentration

Khan, 1. A Mohammad, R. Alam, Md. S. Kabir-ud-Din Effect of Alkylamine Chain Length on the Critical Micelle Concentration of Cationic Gemini Butanediyl-a, oo-bis(dimethylcetylammonium bromide) Surfactant.. Dispersion Sci. Tedtnol, 2009, 30,1486-1493. 

As many gemini surfactants possess lower critical micelle concentrations (CMC) than their single-chained analogs [3], the pseudogemini complexes possessed CMC s lower than those of the individual ligand surfactants. 

A series of cationic gemini surfactants, alkanediyl-ot,a)-bis[di(2-hydro-xylethyl) dodecylammonium] dibromide (abbreviated as 12-S-12 (OH), with s = 4, 6, 8 and 10 methylenes) have been synthesized, and their aggregation properties in aqueous solution have been studied by surface tension, calorimetry, H NMR, DLS, and TEM. Two critical aggregation concentrations are observed for these surfactants. These surfactants start to form dimers at concentrations well below their critical micelle concentrations (CMC). Above the CMC, these surfactants can form both micelles and vesicles spontaneously with a micelle-to-vesicle transition.The formation and characterization of catanionic vesicles by newly synthesized lysine- and... 

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