Regensburg 2002 – wissenschaftliches Programm

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SYPF: Struktur und Dynamik in dünnen Polymerfilmen

SYPF 1: Structure and Dynamics in Thin Polymer Films

SYPF 1.12: Vortrag

Donnerstag, 14. März 2002, 15:50–16:10, H37

Diffusion controlled crystallization of PEO on micropatterned surfaces — •Evelyn Meyer and Hans-Georg Braun — Institut für Polymerforschung / Max-Bergmann Zentrum für Biomaterialien, D-01069 Dresden, Hohe Str. 6

Ultrathin amorphous PEO layers with pre-defined micrometer sized patterns are prepared by dewetting on microheterogeneous (hydrophilic/hydrophobic) surfaces. The surface patterning results from E-BEAM lithography of self-assembled monolayers. PEO layers prepared by dip-coating are formed on the hydrophilic parts of the surface while hydrophobic parts are dewetted. Amorphous PEO films can be created on closed confined pattern which are metastable with respect to crystallization in the initial state. Heterogeneous crystallization can be initiated by contact with an AFM tip. Crystallization of the PEO layers results in highly branched morphological structures typical for diffusion controlled aggregation processes.

For the first time we could study diffusion controlled growth features within pre-defined microstructures. The most striking influence on the morphological growth features results from the pre-patterning of the PEO film. Within the wetted areas characteristic features of the branched elements such as tip-width and correlation length in confined structures can be influenced by the growth velocity and consequently growth features during the solidification and by the crystallization temperature .