Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 26: POSTER Dynamics and Diffusion
CPP 26.4: Poster
Donnerstag, 30. März 2006, 17:00–19:00, P2
Neutron Spectroscopy on Polymers Confined to Nanoporous Glasses — •Andreas Schönhals1, Harald Goering1, Bernhard Frick2, and Reiner Zorn3 — 1Bundesanstalt für Materialforschung und prüfung, Unter den Eichen 87, D-12205 Berlin — 2Institut Max von Laue - Paul Langevin (ILL) 6, rue Jules Horowitz, B.P. 156, F-38042 Grenoble Cedex 9 — 3Forschungszentrum Jülich, Institut für Festkörperforschung, D-52425 Jülich
The behavior polymers confined to geometries of a nanometer scale has become an interesting field. Neutron scattering (NS) is valuable tool to investigate such systems because of the high penetration depth of neutrons. Incoherent NS was carried out on poly(dimethyl siloxane) and poly(methyl phenyl siloxane) confined to Sol/Gel-glasses (7.5, 5.0, 2.5 nm). To cover a broad dynamical range of the scattering function S(Q,E) time-of-flight and backscattering are combined. For the frequency range of the Boson peak the vibrations at lowest frequencies are depressed by the confinement. Elastic scans were carried out and the mean square displacement msd was calculated. Above Tg the characteristic increase of the msd found for the bulk is strongly influenced by the confinement but for both materials in a different manner. The main influence of the confinement on S(Q,t)=FT(S(Q,E)) is an broadening of S(Q,t) with increasing confinement. These results are discussed together with dielectric measurements.