Structural changes of poly(butadiene)-poly(ethyleneoxide) diblock-copolymer micelles induced by a cationic surfactant: Scattering and cryogenic transmission electron microscopy studies
| Autor: | Thomas Hellweg, Gerhard H. Findenegg, Hans von Berlepsch, Anette Nordskog, Helmut Schlaad, Christoph Böttcher, Holger Egger |
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| Rok vydání: | 2003 |
| Předmět: |
Hydrodynamic radius
Materials science Light Polymers Biophysics Neutron scattering Micelle Biophysical Phenomena Polyethylene Glycols Nuclear magnetic resonance Dynamic light scattering Cations Butadienes Copolymer Scattering Radiation Physics::Chemical Physics Micelles Neutrons Scattering Cationic polymerization Quaternary Ammonium Compounds Condensed Matter::Soft Condensed Matter Microscopy Electron Crystallography Elastomers Transmission electron microscopy |
| Zdroj: | Physical Review E. 68 |
| ISSN: | 1095-3787 1063-651X |
| DOI: | 10.1103/physreve.68.011406 |
| Popis: | Micelles of the diblock copolymer poly(butadiene)-poly(ethyleneoxide) $({\mathrm{B}}_{40}\ensuremath{-}b\ensuremath{-}{\mathrm{EO}}_{62})$ and mixed micelles of this polymer with the cationic surfactant dodecyltrimethylammonium bromide $({\mathrm{C}}_{12}\mathrm{TAB})$ 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 $\ensuremath{\approx}30\mathrm{nm}.$ The spherical mixed micelles obtained upon addition of ${\mathrm{C}}_{12}\mathrm{TAB}$ 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. |
| Databáze: | OpenAIRE |
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