Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 7: POSTERS Rheology

CPP 7.10: Poster

Montag, 25. Februar 2008, 16:45–19:00, Poster A

Evolution of complex defects in cylinder phase of block copolymers: Experiment and Simulations — •Larisa Tsarkova¹, Andriana Horvat¹, Agur Sevink², and Andrey Zvelindovsky³ — ¹Physikalische Chemie II, Universität Bayreuth, Germany — ²Soft Condensed Matter Group,Leiden Institute of Chemistry, Leiden University, The Netherlands — ³Centre for Materials Science, Department of Physics, Astronomy and Mathematics, University of Central Lancashire, Preston, United Kingdom

We study and classify typical and specific 2D defects which are repeatedly observed in thin films of cylinder-forming block copolymers upon long-term annealing as well as in simulations based on the dynamic self-consistent mean field theory (DSCFT). We demonstrate that pure topological arguments are not sufficient to characterize the stability and mobility of defects. Instead, specific features of block copolymer materials should be taken into account. In cylinder-forming block copolymers, representative defect configurations provide connectivity of the minority component and indicate the overall morphological evolution under given annealing conditions. The formation of specific non-topological neck-defects is tentatively similar to the initial stages of membranes/vesicles fusion. Lateral propagation velocity of a complex 3T-Junction was measured with in-situ SFM. Comparison with the DSCFT simulations suggests that lateral defect motion is diffusion-driven and indicates weak involvement of the bottom (wetting) layer in the lateral ordering of the structures at the free surface.