Project Details
Projekt
Hydrodynamic interactions along polymers and between colloidal particles as well as the dynamics of vesicles in microflows
Applicant
Professor Dr. Walter Josef Zimmermann
Subject Area
Theoretical Condensed Matter Physics
Term
from 2004 to 2011
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 5426714
Flow induced deformations of polymers, which take place at the nano- and micrometer scale can be observed only recently. The second major effect of the complex polymer-flow interaction is the opposite, namely that the polymer motion causes flow perturbations which are yet unobserved and have dramatic consequences for macroscopic polymer flows. Any moving part of a polymer perturbs the fluid motion and this in turn perturbs the motion of other parts of the polymer. This so-called hydrodynamic interaction (HI) depends an the polymer conformation, it is nonlinear and decreases only slowly with the distance between the interacting parts. lt affects the Brownian motion of single polymers and also causes an interaction of nonoverlaping neutral polymers. Despite these important facts the HI is often neglected in mesoscopic models. Depending an the type of polymer motion, the size of the polymer and its internal structure, the environment of the polymer and the surface structure of channel boundaries, the HI may be more or less important, but this is not known a priory. Therefore, the aim of this project is to determine the HI effects for a variety "model experiments" an polymers, vesicles and actin networks in flows. Some of these experiments have already been discussed with the collaborating experimental groups prior to this proposal. The bead friction coefficients which are used to describe the HI effects in common beadspring models for polymers will be determined by comparing simulations and experiments in order to reach a more quantitative level in this field. With the intended theoretical studies and the comparisons between Brownian dynamics simulations and experiments we can contribute to the insight about the relevant building blocks of more satisfying macroscopic theories of polymer solutions as well as to the understanding of important small scaled flows and transport.
DFG Programme
Priority Programmes
