Dresden 2011 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 23: Poster: Semicrystalline Polymers, Polymer Crystallization and Self-Assembly
CPP 23.17: Poster
Dienstag, 15. März 2011, 18:00–20:00, P2
Supramolecular Self-Assembly of Hydrogen Bonded Bis-Urea Based Molecules — •Roozbeh Shokri1,2, Ashok Narladkar2, Laurent Simon2, Fraçois Vonau2, Laurent Bouteiller3, and Günter Reiter1,4 — 1Physikalisches Institut, Universität Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany — 2Institut de Science des Matériaux de Mulhouse (IS2M-LRC7228), 4 rue des Frères Lumière, 68093 Mulhouse, France — 3Laboratoire de Chimie des Polymères, UMRb7610, Université Pierre et Marie Curie, 4 place Jussieu, 75252 paris CEDEX 05, France — 4Freiburg Institute for Advanced Studies (FRIAS), 79104, Freiburg, Germany
The process of self-assembly has been investigated by AFM analysis for three different bis-urea substituted toluene molecules, EHUT, 3EOUUT and C12EHUT with different side chains. Indirect measurements (neutron-scattering,...) and calculations led to conclude that in solution EHUT molecules can form long supramolecular nanotubes at specific conditions of temperature and concentration. Here, we studied the possibility to stabilize these nanotubes on a surface and see them directly by AFM. Our study, however, presents evidences for layered structures on mica with a quantized step-height of around 2 nm. We prove that within these layers the molecules are organized in a unique upward conformation and form ribbons through hydrogen bonding. Molecules with different side-groups, 3EOUUT and C12EHUT showed characteristic lamellar and triangular morphologies when deposited on graphite, reflecting the 3-fold anisotropy of the atomic lattice of graphite. The second layer in registry with the first layer was observed.