title: Almost fooled again: new insights into cesium dodecyl sulfate micelle structures.
abstract: Replacing sodium with cesium as the counterion for dodecyl sulfate in aqueous solution results in stronger complexation and charge shielding, which should lead to larger micelles and ultimately to a cylindrical structure (cf. spheres for sodium dodecyl sulfate), but small angle X-ray scattering (SAXS) and small angle neutron scattering patterns previously have been interpreted with ellipsoidal micelle models. We directly image CsDS micelles via cryo-transmission electron microscopy and report large core-shell spherical micelles at low concentrations (≤2 wt %) and cylindrical micelles at higher concentrations (5.0 and 8.1 wt %). These structures are shown to be consistent with SAXS patterns modeled using established form factors. These findings highlight the importance of combining real and reciprocal space imaging techniques in the characterization of self-assembled soft materials.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States.
authors.forename: Han Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Manickam
authors.initials: M
authors.lastname: Adhimoolam Arunagirinathan
authors.forename: Apostolos
authors.initials: A
authors.lastname: Vagias
authors.forename: Sangwoo
authors.initials: S
authors.lastname: Lee
authors.forename: Jayesh R
authors.initials: JR
authors.lastname: Bellare
authors.forename: H Ted
authors.initials: HT
authors.lastname: Davis
authors.forename: Eric W
authors.initials: EW
authors.lastname: Kaler
authors.forename: Alon V
authors.initials: AV
authors.lastname: McCormick
authors.forename: Frank S
authors.initials: FS
authors.lastname: Bates