Dresden 2011 – scientific programme
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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
Tuesday, March 15, 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 Rg ∼ N1/2 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.