Dresden 2014 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 37: Poster Session 2

CPP 37.6: Poster

Mittwoch, 2. April 2014, 15:00–19:00, P3

Single Molecule Reorientation Dynamics in Deformed Polymethylacrylate Melts — •Stefan Krause, Martin Neumann, Robert Magerle und Christian von Borczyskowski — Fakultät für Naturwissenschaften, Technische Universität Chemnitz, D-09107 Chemnitz, Germany

The fluorescence of a single molecule (SM) is a very sensitive probe for the molecules environment and changes of the fluorescence lifetime, emission wavelength, and polarization can report spatial and temporal changes in the environment of the fluorescent dye. Here we report on polarization sensitive SM microscopy in thin films of polymethylacrylate (PMA) melts that are stretched in a microtensile testing setup. Functionalized perylene diimide dyes embedded in the PMA film report their molecular reorientation dynamics and changes within their local environment via polarization sensitive SM microscopy. In control experiments we studied the stress-strain behaviour and the stress relaxation of the PMA films. This experiment provides insights into the steric coupling processes between fluorescent probe molecules and polymer chains which are not accessible with other microscopy techniques. The data show a continuous transition from an unisotropic distribution of orientations to a more isotropic distribution during deformation of the polymer. In addition, the experiment allows for the direct observation of reorientation of the molecules after deformation which is in close relation with the relaxation of the polymer films.