Berlin 2012 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 33: Polymer Dynamics
CPP 33.2: Talk
Thursday, March 29, 2012, 10:00–10:15, C 264
Orientation autocorrelation function of the 2nd Legendre polynomial for Rouse chains with fixed ends — •Semjon Stepanow and Kay Saalwächter — Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, D-06099 Halle, Germany
We have calculated the autocorrelation function of the 2nd Legendre polynomial of the segmental orientation for a Rouse chain with fixed ends. This function is relevent for nuclear magnetic resonance (NMR) measures of chain dynamics in polymer networks [1] and entangled melts [2], for which a chain with fixed ends represents the simplest model for the time range from the segmental relaxation time up to the onset of cross-link or tube constraints. The time-dependent part of the ACF is given by c1 t−1/2 + c2 t−1. It thus deviates from free-Rouse result ∼ t−1, and compares favorably with experimental data [1,2].
[1] K. Saalwächter, A. Heuer, Macromolecules 39 (2006) 3291
[2] A. Herrmann, V. N. Novikov, and E. A. Rössler, Macromolecules 42 (2009) 2063; F. Vaca Chavez, K. Saalwächter, Phys. Rev. Lett. 104 (2010) 198305