Dresden 2003 – wissenschaftliches Programm

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SYSE: Simulation and experiment

SYSE 1: Simulation and experiment - spanning the bridge between microscopic and macroscopic scales

SYSE 1.2: Hauptvortrag

Dienstag, 25. März 2003, 11:30–12:00, ZEU/160

Self-assembled structures in binary polymer brushes — •Marcus Müller — Institut für Physik, WA 331, Johannes Gutenberg Universität, D55099 Mainz

We investigate the structure and phase behavior of a two-component (binary) polymer brush in a solvent within self-consistent field theory (SCFT) as a function of the chains’ stretching, the composition, the incompatibility and the solvent selectivity. Grafting the chains irreversible prevents macrophase separation and the chains assemble into three dimensional structures with lateral periodicity. At small incompatibilities a ripple phase is formed where different species aggregate into an array of parallel cylinders. At larger incompatibilities or asymmetric composition two “dimple”phases become stable, where different species form clusters which arrange on a quadratic (checkerboard structure) or hexagonal lattice. The results of SCFT are compared to experiments (S. Minko et al, IPF, Dresden) and ways to tune the morphology and surface properties via solvent selectivity or external interactions are discussed. The influence of fluctuations in the spatial distribution of grafting points on the morphology is investigated by computer simulations.