Münster 1999 – scientific programme

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DY: Dynamik und Statistische Physik

DY 20: POSTER I

DY 20.5: Poster

Tuesday, March 23, 1999, 09:30–13:00, F

Single Tethered Polymer in Uniform Flow — •D. Kienle, R. Rzehak, and W. Zimmermann — Institut für Festkörperforschung und Forum Modellierung

Due to the development of new experimental techniques, the study of single polymers under external fields has attracted considerable interest in recent years.

In order to obtain scaling laws analytically the blob model has been proposed. By using Brownian dynamics simulation one gets a better microscopic insight in the complex interaction of the fluid and the polymer. In a recent investigation we obtained by this method different scaling exponents. This may be explained by a shortcoming of the blob model, which assumes, that the polymer is non-draining everywhere.

But this is incorrect because the penetration of the flow into the polymer coil depends on its local diameter. The latter is very small near the teatherpoint and assumes its maximum close to the free chain end. Furthermore even close to equilibrium, where the spherical coil shape is only slightly disturbed, a partial draining is observed.

We propose a modification of the blob model that takes these findings onto account phenomenologically and qualitatively reproduces the simulation results.

In order to include more realistic flow fields we also modified the blob-model for shear- and Poiseuille flow.