Dresden 2009 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 21: Polymer Physics II
CPP 21.4: Vortrag
Mittwoch, 25. März 2009, 10:15–10:30, ZEU 114
Studying Radical Polymerization by Single Molecule Spectroscopy — •Dominik Wöll1, Frans de Schryver2, Klaus Müllen3, and Johan Hofkens2 — 1Zukunftskolleg/Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany — 2Laboratory for Photochemistry and Spectroscopy, Celestijnenlaan 200 F, Katholieke Universiteit Leuven, 3001 Heverlee, Belgium — 3Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
The possibility to observe single molecules, first realized about 20 years ago, has opened up a fascinating field of research. Even though polymers are popular systems for single molecule spectroscopy studies, the process of radical polymerization has so far not been studied at the single molecule level.
We investigated how the molecular motion of single fluorescent probes changes during the synthesis of polystyrene, polystyrene networks and polymethylmethacrylate by bulk radical polymerization. As probes, we have chosen perylene diimide derivatives of different sizes and functionalities. The translational motion over the entire conversion range from free diffusion to immobilization of the dyes could be followed by a combination of fluorescence correlation spectroscopy and wide-field microscopy. In contrast to ensemble measurements, the evolution of heterogeneities could be strikingly visualized by SMS. Such heterogeneities not only influence the progress of polymerization but also the properties of the synthesized polymer and are especially pronounced during the formation of networks.