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PO: Polymerphysik

PO 13: Spektroskopische Methoden

PO 13.2: Vortrag

Dienstag, 2. März 1999, 16:20–16:40, HS 19

Analyse der Struktur eines Dendrimers mit Hilfe der Neutronenkleinwinkelstreuung — •D. Pötschke¹, M. Ballauff¹, P. Lindner², M. Fischer³, and F. Vögtle³ — ¹Polymer-Institut, Universität Karlsruhe, Kaiserstraße 12, 76128 Karlsruhe — ²Institut Laue-Langevin, BP 156X, 38042 Grenoble, France — ³Kekule-Institut für Organische Chemie und Biochemie, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany

The analysis of a dendrimer of fifth generation by small-angle Neutron scattering (SANS) including contrast variation is presented. The contrast of the dissolved dendrimer towards the solvent is changed systematically which allows to elucidate the radial scattering length density ρ. With ρ and the scattering length density ρ_m of the solvent being known the measured scattering intensity can be decomposed into a term depending on the contrast ρ−ρ_m and a term independent of contrast. The latter contribution is shown to be non-negligible. Its subtraction leads to the corrected intensity which may be evaluated to yield the radial density of the dendrimer. The analysis demonstrates that the dendrimer under consideration here has a compact structure where the density has its maximum at the center of the molecule in agreement with recent theoretical calculations.