Berlin 2008 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 34: POSTERS Polymerphysics
CPP 34.24: Poster
Thursday, February 28, 2008, 17:00–19:30, Poster A
Static and dynamic properties of tethered chains in different surface regimes. Monte Carlo studies. — •Radu Descas1, Jens-Uwe Sommer2, and Alexander Blumen1 — 1Theoretische Polymerphysik, Universität Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg — 2Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, D-01069 Dresden
Using MC simulations combined with scaling arguments we study the adsorption of tethered polymer chains at flat surfaces. The interplays between the grafting density σ, the excluded volume, and the strength of adsorption κ lead to different surface regimes. We suggest a σ − κ phase diagram and focus on the semidilute surface regime and on the oversaturated brush regime. In these regimes we study both the static [1] and the dynamic [2] properties of the chains. Using scaling arguments and computer simulations we analyse the average extension of single chains both parallel and perpendicular to the surface. Especially for the parallel component our simulation results agree well with the scaling predictions. In the semidilute regime the dynamics is well described by a model in which the chains form adsorption blobs. In the oversaturated brush regime the system can be visualized as a brush-like state formed on top of a saturated adsorption layer. Our simulations show that in this regime the dynamics is controlled by three-dimensional blobs.
[1] R. Descas, J.-U Sommer, and A. Blumen, J. Chem. Phys. 125, 214702 (2006).
[2] R. Descas, J.-U Sommer, and A. Blumen, in preparation.