Berlin 2001 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 19: Poster: New Methods, Thin Polymer Films, Monolayers
CPP 19.9: Poster
Donnerstag, 5. April 2001, 12:30–15:00, AT1
Lamellar Orientation in Thin Diblock Copolymer Films - Influence of Molar Mass — •Peter Busch1, Detlef Smilgies2, Dorthe Posselt3, Friedrich Kremer1, and Christine M. Papadakis1 — 1Department of Physics, University of Leipzig, 04103 Leipzig, Germany — 2CHESS, Wilson Lab, Cornell University, New York, USA — 3IMFUFA, Roskilde University, DK-4000 Roskilde, Denmark
Symmetric polystyrene-polybutadiene block copolymers (PS-PB) in the bulk form a microphase-separated, lamellar structure, where the lamellar thickness scales with chain length. In contrast to PS-polymethylmethacrylate (PS-PMMA) thin films, where the selectivity of the two surfaces induces a parallel orientation of the lamellae, we found for PS-PB both the parallel (short chains) and the perpendicular orientation (long chains). There is a continuous transition between the two regimes where coexisting parallel, perpendicular and tilted lamellae are observed.
Combination of AFM [1], X-ray-reflectivity, and grazing incidence small angle X-ray scattering (GISAXS) [2] allowed a full description of the whole film morphology. Most films were prepared by spin coating on silicon, but also other preparation methods are discussed.
1 P. Busch et al., Surface and Interface Analysis, submitted.
2 C.M. Papadakis et al., Experimental report, ESRF, August 2000.