Berlin 2005 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 30: POSTER: Chemical physics

CPP 30.2: Poster

Dienstag, 8. März 2005, 16:30–18:30, Poster TU D

Fluorescence lifetime fluctuations of single molecules in polymer films — •Ruben Schmidt and Frank Cichos — Photonik und Optische Materialien, Institut für Physik, TU Chemnitz, 09107 Chemnitz

The dynamical processes in polymers close to the glass transition involve a wide range of relaxation timescales, which leaves the glass transition in part still not well understood. We employ single fluorescent molecules to probe local fluctuations of the polymer environment to give more detailed information on the glass transition itself. We present measurements of fluorescence lifetime fluctuation of single dye molecules embedded in thin polymer films. While modifications of the radiative rate of the dye molecules due to local density fluctuations are not observed, fluctuations due to non-radiative channels based on conformational changes of the dye molecule are found. Statistical analysis of these fluctuations allow tracking of environmental fluctuations over 3 to 4 orders of magnitude in time.