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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 38: Computational Physics of Soft Matter I
CPP 38.6: Vortrag
Mittwoch, 18. März 2015, 11:15–11:30, C 264
Conformations of a Long Polymer in a Melt of Shorter Chains: Generalizations of the Flory Theorem — •Michael Lang1, Michael Rubinstein2, and Jens-Uwe Sommer1,3 — 1Leibniz Institute of Polymer Research Dresden, Hohe Straße 6, 01069 Dresden, Germany. — 2Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, United States. — 3Institute of Theoretical Physics, Technische Universität Dresden, Zellescher Weg 17, 01062 Dresden, Germany.
Large scale simulations of the swelling of a long N-mer in a melt of chemically identical P-mers are used to investigate a discrepancy between theory and experiments. Classical theory predicts an increase of probe chain size R∼ P−0.18 with decreasing degree of polymerization P of melt chains in the range of 1<P<N1/2. But both experiment and simulation data are more consistent with an apparently slower swelling R∼ P−0.1 over a wider range of melt degrees of polymerization. This anomaly is explained by taking into account the recently discovered long range bond correlations in polymer melts and corrections to excluded volume. We generalize the Flory theorem and demonstrate that it is in excellent agreement with experiments and simulations.