Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: Poster: Confinement of Polymers in Nanoscopic Layers - How Much do Properties Change?

CPP 21.6: Poster

Dienstag, 15. März 2011, 18:00–20:00, P2

Form factor of polymer melts: Deviations from ideal Gaussian behavior — •Julia Zabel¹, Caleb Dyer², Mark Dadmun², Hendrik Meyer¹, Joachim Wittmer¹, and Joerg Baschnagel¹ — ¹Insitut Charles Sadron, CNRS, 23 rue du Loess, 67037 Strasbourg, France — ²Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA

With a disarmingly simple argument Flory predicted that a flexible polymer in a melt behaves as an ideal, 3 dimensional random walk, its step length Gaussian distributed. This hypothesis is based on excluded volume screening in a dense melt. The Gaussian coil gives rise to such important scaling laws as R_g ∼ N^1/2 which are fundamental in modern polymer physics. Over the last decade the Flory hypothesis has been revisited and corrections suggested [Semenov et al, Euro Phys. J. E, 12 (2003)]. Coarse grained simulation mod- els support these corrections [Wittmer et al, EPL, 77 (2007)]. Most recently small angle neutron scattering experiments have been performed on high molecular weight PIB and PDMS melts. The results will be presented here and their deviations from ideal behavior discussed.