engleski

New catanionicmixtures of didodecyldimethylammonium bromide/sodium dodecylbenzene sulfonate/water with special reference to spontaneous formation of vesicles. II. Size and shape analysis by saxs, light scattering, cryo-TEM, and light microscopy

Mixed catanionic solutions of sodium dodecybenzenesulfonate (SDBS) and didodecyldimethylammonium bromide (DDAB) have been investigated by dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS), with special emphasis on the aggregation behavior and structures of particles spontaneously formed in dependence on the composition of the catanionic mixture SDBS/DDAB/H2O. Phase behavior and particle sizes have been determined. Changes of the mixture composition within two ranges (in the SDBS-rich corner and in the DDAB-rich corner in the highly diluted regime) correlated well with the reported changes in the vesicular and micellar sizes. In the diluted SDBS and DDAB regimes mentioned above, monodispersed micelles and monodispersed unilamellar vesicles have been found, respectively. Investigations performed in the solutions using Cryo-TEM and light microscopy with polarizing equipment confirmed the DLS and SAXS results. The existence of polydispersed unilamellar and oligovesicular vesicles spontaneously formed in the mixtures at wtot ¼ (0.005– 0.02) was detected. Micrographs have also shown the giant vesicle formation as well as the coacervate phase formation at wtot ¼ 0.0015, xSDBS ¼ 0.4.

associate ; cryo-TEM ; DLS ; catanionic mixture ; micelles ; SAXS ; vesicles

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