title: Structural changes of poly(butadiene)-poly(ethyleneoxide) diblock-copolymer micelles induced by a cationic surfactant: scattering and cryogenic transmission electron microscopy studies.
abstract: Micelles of the diblock copolymer poly(butadiene)-poly(ethyleneoxide) (B40-b-EO62) and mixed micelles of this polymer with the cationic surfactant dodecyltrimethylammonium bromide (C12TAB) were investigated using static and dynamic light scattering and small-angle neutron scattering. It is shown that the surfactant induces a major structural change from large mainly rodlike aggregates to smaller spherical mixed micelles. The rodlike assemblies found in the absence of surfactant have a contour length L of ca. 500 nm and a diameter d approximately 30 nm. The spherical mixed micelles obtained upon addition of C12TAB possess a hydrodynamic radius of 15 nm and still contain several polymer molecules. The results of the scattering experiments are consistent with observations of the aggregates by cryogenic transmission electron microscopy.
authors.affiliation: TU Berlin, Stranski-Laboratorium f. Physikalische und Theoretische Chemie, Strasse des 17.Juni 112, D-10623 Berlin, Germany.
authors.forename: Anette
authors.initials: A
authors.lastname: Nordskog
authors.forename: Holger
authors.initials: H
authors.lastname: Egger
authors.forename: Gerhard H
authors.initials: GH
authors.lastname: Findenegg
authors.forename: Thomas
authors.initials: T
authors.lastname: Hellweg
authors.forename: Helmut
authors.initials: H
authors.lastname: Schlaad
authors.forename: Hans
authors.initials: H
authors.lastname: Von Berlepsch
authors.forename: Christoph
authors.initials: C
authors.lastname: Böttcher
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D002070:Butadienes / Q000737:chemistry*; D002412:Cations; D020724:Elastomers; D008027:Light; D008823:Micelles; D008854:Microscopy, Electron / Q000379:methods*; D009502:Neutrons; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012542:Scattering, Radiation
chemical_list: D002070:Butadienes; D002412:Cations; D020724:Elastomers; D008823:Micelles; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D011092:Polyethylene Glycols; C028834:polybutadiene; C022806:dodecyltrimethylammonium