Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 30: Polymerphysics II
CPP 30.6: Vortrag
Donnerstag, 28. Februar 2008, 15:15–15:30, C 130
On the statistics of Gaussian two and three-dimensional networks: Fluctuations of junctions and collapse driven by structure. — •Michael Lang1,2, Sergey Panyukov3, Michael Rubinstein2, and Jens-Uwe Sommer1 — 1Leibniz-Institute for polymer Research, Hohe Str. 6, 01069 Dresden, Germany — 2Department of Chemistry, University of North Carolina, 27599 Chapel Hill, N.C., USA — 3P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow, Russian Federation
We investigate ideal Gaussian networks both analytically and with computer simulations using the Bond Fluctuation model with and without excluded volume interactions. The focus of this study is on fluctuations and the collapse of networks with different connectivity and dimensionality.
We show that the size of a perfect square 2D network made from n2 Gaussian chains with N monomers each is Rg ∼ N1/2· log(n). Thus, fluctuations in two-dimensional networks diverge logarithmically with the size of these films while fluctuations of three-dimensional networks with cubic structure is ∼ N1/2 and do not increase with their size. We study the cross-over between two and three-dimensional networks by following the dependence of junction fluctuations on the thickness of films.
The results of model systems are compared with more realistic networks in order to understand the effect of disorder on the properties of the network and fluctuations of network junctions.