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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 19: POSTER: Micro and Nano Fluidics

CPP 19.11: Poster

Mittwoch, 28. März 2007, 16:00–18:30, Poster B

Correlating macroscopic viscosity and microscopic structure of the tri-block copolymer EO₂₀-PO₇₀-EO₂₀ — •Marco Walz¹, Max Wolff², Nicole Voss¹, Andreas Magerl¹, and Hartmut Zabel² — ¹Chair for Crystallography and Structural Physics, University of Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen, — ²Chair for Condensed Matter Physics, Ruhr-University Bochum, Universitätsstr. 150, 44780 Bochum

A neutron scattering study on the structure of the tri-block copolymer Pluronic^.07exR20D P123 (EO₂₀-PO₇₀-EO₂₀) in aqueous solution near a solid boundary is presented. An initially unexpected hysteresis found in the macroscopic viscosity is correlated with solid state orderings observed by near surface diffraction. The alignment of the structures is sensitive to the surface and its chemical termination. With temperature, the fcc lattice constant varies between 218 Å and 231 Å for 18^∘C and 32^∘C, respectively. The rocking curves, also with hysteresis, have a clear two-component profile giving information about long range correlations and short range disorder of the micelles.

The authors gratefully acknowledge the financial support by the DFG grants MA801/12-1 and ZA161/18-1 within the priority program (SPP) 1164 and the BMBF grant ADAM 04ZAE8BO.