Fleischer, G. ; Karger, J. ; Stühn, B. (1997)
Chain diffusion in the melt of an asymmetric diblock copolymer in the disordered and ordered state.
In: Colloid and Polymer Science, 275 (9)
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The self-diffusion in a polystyrene-b-polyisoprene diblock copolymer with a strongly asymmetric composition was investigated with dependence on temperature by pulsed field gradient (PFG) NMR. The diblock shows with decreasing temperature a disorder-to-order-transition at T-ODT = 393 K from a micellar liquid-like to a bcc ordered state which was recently measured by SAXS [M. Schwab and B. Stühn, Phys. Rev. Lett. (1996) 76: 924]. Two diffusivities were observed, one of the free diblock chains and one of the diblock chains fixed in micelles. The volume fraction of free chains decreases with decreasing temperature. The diffusivity of the free chains must be related to chain stretching. The experiments show that within the time of the NMR experiment (300 ms) there is no exchange between the diblock chains in the free state and those fixed in the core of the micelles.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 1997 |
| Autor(en): | Fleischer, G. ; Karger, J. ; Stühn, B. |
| Art des Eintrags: | Bibliographie |
| Titel: | Chain diffusion in the melt of an asymmetric diblock copolymer in the disordered and ordered state |
| Sprache: | Englisch |
| Publikationsjahr: | September 1997 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Colloid and Polymer Science |
| Jahrgang/Volume einer Zeitschrift: | 275 |
| (Heft-)Nummer: | 9 |
| Kurzbeschreibung (Abstract): | The self-diffusion in a polystyrene-b-polyisoprene diblock copolymer with a strongly asymmetric composition was investigated with dependence on temperature by pulsed field gradient (PFG) NMR. The diblock shows with decreasing temperature a disorder-to-order-transition at T-ODT = 393 K from a micellar liquid-like to a bcc ordered state which was recently measured by SAXS [M. Schwab and B. Stühn, Phys. Rev. Lett. (1996) 76: 924]. Two diffusivities were observed, one of the free diblock chains and one of the diblock chains fixed in micelles. The volume fraction of free chains decreases with decreasing temperature. The diffusivity of the free chains must be related to chain stretching. The experiments show that within the time of the NMR experiment (300 ms) there is no exchange between the diblock chains in the free state and those fixed in the core of the micelles. |
| Fachbereich(e)/-gebiet(e): | 05 Fachbereich Physik > Institut für Festkörperphysik (2021 umbenannt in Institut für Physik Kondensierter Materie (IPKM)) 05 Fachbereich Physik |
| Hinterlegungsdatum: | 27 Feb 2010 12:29 |
| Letzte Änderung: | 05 Mär 2013 09:32 |
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