Dresden 2011 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 13: Focused Session: Confinement of Polymers in Nanoscopic Layers - How Much do Properties Change? I
CPP 13.5: Vortrag
Dienstag, 15. März 2011, 12:30–12:45, ZEU 160
Chain Dynamics of Polymers Confined to Ordered Nanoporous Alumina Membranes — •Cornelius Franz1, Salim Ok2, Gopalakrishnan Rengarajan2, Fabián Vaca Chávez1, Christian G. Hübner3, Martin Steinhart2, and Kay Saalwächter1 — 1Institut für Physik - NMR, Universität Halle, Betty-Heimann-Str. 7, 06120 Halle — 2Institut für Chemie, Universität Osnabrück — 3Institut für Physik, Universität Lübeck
The nanoscopic confinement effect of hard neutral or attractive walls on the dynamics of polymer chains in the melt is studied by solid-state NMR. We apply a variety of NMR techniques to the characterization and the elucidation of chain dynamics in true model composites based on self-ordered nanoporous alumina with well-defined geometry and the possibility to tune the properties of the inorganic surface.
The long-time dynamics of entangled melts is significantly different from the bulk and rather anisotropic in a layer of a few nm close to the weakly interacting wall, and that the effect appears to scale with the entanglement spacing. Further preliminary studies demonstrated that these effects are orientation dependent, and also occur for nominally unentangled melts.
We also studied the large-scale diffusion by pulsed-gradient NMR and the infiltration kinetics by confocal fluorescence microscopy where we have monitored the infiltration of dye-doped polymer into self-ordered AAO in situ. Pore-wall modification experiments were verified by quantitative high-resolution NMR.