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CPP: Chemische Physik und Polymerphysik

CPP 1: Thin Films and Surfaces I

CPP 1.3: Vortrag

Montag, 27. März 2006, 10:15–10:30, ZEU Lich

Flow of a complex liquid near a solid interface: SPM studies — •Hendrik Hähl, Ludovic Marquant, Daniel Podzimek, Renate Fetzer, and Karin Jacobs — FR 7.2 Experimentalphysik - Weiche Materie, Universität des Saarlandes, D-66123 Saarbrücken

Dewetting of structured liquids is a very complex process. We investigate thin block-copolymer films composed of polystyrene-block-polyethylen/propylen (PS/EP) retracting from silanized silicon wafers. The equilibrium layer structure of the block-copolymer film vanishes in the presence of shear flow, giving way to a more complex structure. By tapping mode SPM, we can detect PS cylinders in a matrix of PEP. These cylinders are aligned parallel to the moving three-phase contact line. Additional to the free surface of the film, we are interested in the film behaviour near the solid substrate. We found a novel method to scan the microdomain structure of the block-copolymer film just at this interface with SPM resolution. The alignment of the cylinders we also found here gives evidence to a nonzero slippage velocity.