Self-organization of the ternary didecyldimethylammonium bromide/octyl-β-D-glucopyranoside/water system

The spontaneous and thermodynamically stable mixed vesicles constituted by a double-chain cationic surfactant with 10 carbon atoms hydrophobic tail, didecyldimethylammonium bromide (di-C(10)DMAB), and a nonionic single-chain surfactant, octyl-beta-D-glucopyranoside (OBG), have been characterized in aqueous media by means of a series of experimental techniques, as well as a theoretical approach. Conductivity data allow for the determination of the concentrations at which the monomer-to-vesicle (CVC*) and/or vesicle-to-micelle (CMC*) transitions occur. Electrophoretic mobilities, obtained from laser-doppler-electrophoresis experiments, permit the determination of zeta-potentials and, from them, the surface charge density of the vesicle aggregates. Cryogenic transmission electron microscopy (cryo-TEM) provides pictures of the vesicles, their size and shape being, thus, determined. Finally, the sensitivity of the emission spectra of some fluorescent probes, such as the cationic TNS and the nonionic PRODAN, to the polarity of the environment, allow for a complete study of different pre- and post-vesicle microdomains, of variable rigidity and micropolarity. This, in turn, yield interesting information about the vesicle surface and bilayer, as well as, about the existence of clusters and/or nanoaggregates prior to the formation of vesicles, as was proposed by us in a previous paper.