Berlin 2005 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 6: SYMPOSIUM: Polymer networks and beyond: From molecular structure to materials and biological functions

CPP 6.2: Hauptvortrag

Samstag, 5. März 2005, 08:40–09:10, TU C243

Random network media and their universal properties: Landau theory and beyond — •Paul Goldbart — Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, U.S.A.

Random network solids, as formed e.g. by the vulcanization of polymeric liquids, will be examined via an order-parameter based Landau approach. Despite its simplicity, this approach yields a rich, universal picture of random solids, even at the classical level, including their heterogeneity and rigidity. By going beyond the classical level, via the incorporation of fluctuation effects, connections with percolation and random resistor networks emerge, and the scaling of the shear modulus near the random solidification transition can be determined. In addition, the influence of Goldstone-type excitations can be ascertained, and seen to be especially strong in low-dimensions. Extensions to more elaborate settings, such as vulcanized polymer blends and nematic elastomers, can be made. A simple cavity-based scheme sheds light on the origins of results first obtained via replica-based approaches.

The contributions of many collaborators, most notably Annette Zippelius, are gratefully acknowledged.