Dresden 2009 – wissenschaftliches Programm
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SYSO: Symposium Self-organizing Surfaces and Interfaces
SYSO 3: Self-Organizing Surfaces and Interfaces - Posters
SYSO 3.10: Poster
Mittwoch, 25. März 2009, 17:30–19:30, P3
Multiscale study of crystallization in diblock copolymer thin films at different supercooling — •Christine M. Papadakis1, Charles Darko1, Ezz Metwalli1, Ioan Botiz2, Günter Reiter2, Dag W. Breiby3, Jens W. Andreasen4, Stephan V. Roth5, and Detlef-M. Smilgies6 — 1TU München, Physikdepartment E13, Garching — 2Institut de Chimie de Surfaces et Interfaces, CNRS, Mulhouse, France — 3Department of Physics, Norwegian University of Science and Technology, Trondheim — 4Risø National Laboratory, Roskilde, Denmark — 5HASYLAB at DESY, Hamburg — 6CHESS, Cornell University, Ithaca NY, USA
In block copolymers with a crystalline block, the orientation of the crystalline chain stems with respect to the internal interfaces depends on the degree of supercooling. The thin film geometry offers the possibility to create oriented mesostructures and to gain detailed knowledge on the crystalline orientation. We have studied thin films of polystyrene-b-poly(ethylene oxide), PS-b-PEO, diblock copolymers in dependence on the degree of supercooling. AFM showed that the crystalline domains (lamellae) consist of grains, which are macroscopic at a low degree of supercooling, but of submicrometer size for strong supercooling. Using grazing-incidence wide-angle X-ray scattering, we could determine the grain orientation distribution function which shows that the chain stems are perpendicular to the lamellae at low supercooling, but tilted at strong supercooling. These results suggest that, at strong supercooling, the crystalline PEO lamellae do not grow homogeneously, but by the formation of small crystallites at the growth front.