Regensburg 2013 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 31: Anomalous Diffusion

DY 31.5: Talk

Thursday, March 14, 2013, 16:00–16:15, H48

Anomalous diffusion in two- and three-dimensional polymer melts — •Hendrik Meyer, Jean Farago, and A.N. Semenov — Intitut Charles Sadron, CNRS UPR22, 67034 Strasbourg, France

Polymers in the melt are known to exhibit subdiffusive monomer dynamics which, for unentangled chains, is well described by the Rouse model. Experiments and simulations have shown that the center of mass of a chain exhibits also subdiffusive behavior, a feature which is not contained in the Rouse model. This feature found recently an unexpected explanation: hydrodynamic interactions are still present in polymer melts and their combination with the viscoelastic properties of the melt explain the observed behavior [1]: there is a short superdiffusive regime followed by subdiffusion until the chain relaxation time. We have now developed the theory of visco-hydrodynamic interactions (VHI) for two-dimensional melts where the superdiffusive regime is strongly enhanced. The theory also takes into account finite-box size effects which strongly modify two-dimensional simulation data. This leads to complex anomalous dynamics which cannot be described by simple power laws [2].

J. Farago et al. Phys. Rev. Lett. 107, 178301 (2011); PRE 85, 051806 (2012); H. Meyer and A.N. Semenov, Phys. Rev. Lett. accepted (2012).