Gummel, JérémieSztucki, MichaelNarayanan, TheyencheriGradzielski, Michael2016-07-012016-07-0120111744-683Xhttps://depositonce.tu-berlin.de/handle/11303/5762http://dx.doi.org/10.14279/depositonce-5382Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.We report on the structural dynamics underlying the formation of unilamellar vesicles upon mixing dilute solutions of anionic and zwitterionic surfactant solutions. The spontaneous self-assembly was initiated by rapid mixing of the surfactant solutions using a stopped-flow device and the transient intermediate structures were probed by time-resolved small-angle X-ray scattering. The initial surfactant solutions comprised of anionic lithium perfluorooctanoate and zwitterionic tetradecyldimethylamine oxide, where the mixtures form unilamellar vesicles over a wide range of concentrations and mixing ratios. We found that disk-like transient intermediate structures are formed at higher concentrations while more elongated forms such as cylinder-like and torus-like micelles are involved at lower concentrations. These differences are attributed to monomer addition mechanism dominating the self-assembly process when the initial concentration is well below the critical micellar concentration of the anionic surfactant, while at higher concentrations the process is governed by fusion of disk-like mixed micelles. This means that the pathway of vesicle formation is determined by the proximity to the critical micellar concentration of the more soluble component.en530 PhysikArticle1744-6848