Higher-order micellar structure

In all cases, these aggregates had a uniform diameter of a few nanometers, that is, on the same length scale as the molecular dimensions. Hence, they appeared to be well-defined supramolecular polymers (rather than micellar or vesicular structures) with the propensity to higher-order structure formation. The exact natureofthelatterwasfoundtodependonthenumberofadditionalN—H G=C type hydrogen-bonding sites in the molecules end groups. 

Naoe, K., Takeuchi, C., Kawagoe, M., Nagayama, K., Imai, M. 2007. Higher order structure of Mucor miehei lipase and micelle size in cetyltrimethylammonium bromide reverse micellar system. J. Chromatography B 850, 277-284. 

When surface active agents are considered, a further complication may be encountered. Because of their surface active nature, the surfactants not only emich at the surfaces, but also form extended structures themselves. At low concentrations, the surfactants remain as dissolved monomers or asssociate to oligomers. However, when the critical micellization concentration (cmc) is surpassed, a cooperative association is activated to micelles (1 to 10 nm) consisting typically of some 50 to 100 monomers. At stiU higher concentrations, or in the presence of cosurfactants (alcohols, amines, fatty acids, etc.), liquid crystalline phases may separate. These phases have an infinite order on the x-ray scale, but may remain as powders on the NMR (nuclear magnetic resonance) scale. When the lamellar liquid crystalline phase is in equilibrium with the liquid micellar phase the conditions are optimal for emulsions to form. The interface of the emulsion droplets (1 to 100 pm) are stabilized by the lamellar liquid crystal. Both the micelles and the emulsions may be of the oil in water (o/w) or water in oil (w/o) type. Obviously, substances that otherwise are insoluble in the dispersion medium may be solubilized in the micelles or emulsified in the emulsions. For a more thorough analysis, the reader is directed to pertinent references in the literature. ... 

---