Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 13: Dünne Polymerfilme
CPP 13.2: Vortrag
Donnerstag, 27. März 2003, 10:30–10:45, ZEU/118
In-situ Study of the Adsorption Kinetics of a Polymer Brush — •M. Himmelhaus1, T. Bastuck1, J. Fick1, L. Livadaru2, H. J. Kreuzer2, and M. Grunze1 — 1Lehrstuhl für Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg — 2Department of Physics, Dalhousie University, Halifax, N. S. B3H 3J5 Canada
The chemical grafting of alkanethiol-terminated poly(ethylene glycol) to a gold substrate from dimethylformamide solution was monitored by in-situ ellipsometry and optical second harmonic generation for several molar concentrations. In the initial stage a single layer of mushroom-like moieties forms which on a much larger time scale is followed by conformational conversion (and further adsorption) to a dense brush of stretched polymers. The characteristic time of the coil-to-brush transition is found to depend linearly on the concentration of the solute. A statistical mechanical theory is developed that accounts fully for all observed details.