Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 13: POSTERS Polymer Physics

CPP 13.10: Poster

Dienstag, 24. März 2009, 14:00–16:30, P3

Mobility of single polymer chains in thin films by widefield fluorescence microscopy — •Bente Marid Ingeborg Flier and Andreas Zumbusch — Fachbereich Chemie, Universität Konstanz, D-78457 Konstanz

Thin polymer films with a thickness of several tens of nanometers are of high interest both for scientific and industrial applications. The adhesion and interdiffusion properties of such films are affected by the mobility of the polymer chains. In order to probe bulk-obscured heterogenities in the chain mobility we use single molecule fluorescence techniques. For this purpose, single fluorescent molecules are covalently attached as labels to the end of a polymer chain and their motion is observed via fluorescence wide-field microscopy. We use two different approaches to investigate dynamical processes. Rotational diffusion of a fluorophor is observed by defocused imaging. Defocussing the sample under investigation leads to patterns in spatial distribution of the emitted photons which are specific for each orientation of the emission dipole. Analysing the orientational dynamics allows the analysis of rotational diffusion. Translational diffusion, by contrast, can be observed by determining the position of the fluorophors and analysing the trajectories by single particle tracking. We present results of investigations of the dependence of polymer chain mobility on chain length and temperature using both approaches.