Berlin 2005 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 5: SYMPOSIUM: Dynamics of multi-component fluids POSTER

CPP 5.29: Poster

Freitag, 4. März 2005, 17:15–19:00, Poster TU D

Correlated defect dynamics in block copolymer melts — •Larissa Tsarkova, Armin Knoll, and Robert Magerle — Physikalische Chemie II, Universität Bayreuth

Block copolymers are fluid materials which self assemble into a variety of highly ordered and complex structures. Very little is known about mechanisms by which order evolves in morphologies on a nanometer scale. With scanning force microscopy we image in-situ the microdomain dynamics in a thin film of polystyrene-block-polybutadiene diblock copolymer while annealing above the glass transition of polystyrene. With unprecedented time resolution we follow the detailed dynamics of characteristic defects with life-time ranging from seconds to hours and lengthscale of correlated motion about several domain spacings (100 nm). Topological constrains favore various annihilation mechanisms: through local transient phases such as spherical domains, lamella, disordered state, or elastic deformations of the microdomains. Comparison of the typical time between the repetitive defect states with characteristic diffusion coefficients suggests that the motion proceeds via correlated movement of clusters of chains.