Berlin 2008 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 20: POSTERS Driven Soft Matter
CPP 20.18: Poster
Wednesday, February 27, 2008, 16:00–18:30, Poster A
Ultrafast Dynamics in Nanolayered Polyelectrolyte/ Metallic Structures Studied by Femtosecond Pump-Probe Spectroscopy — •Mareike Kiel1,2, Wolfram Leitenberger1, and Matias Bargheer1,2 — 1Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Potsdam — 2Universität Potsdam
The dynamic response of hybrid nanolayer systems composed of polyelectrolytes and metals upon optical excitation is studied by ultrafast pump-probe experiments. Relative intensity changes of transient absorption and reflection spectra are measured with light in the visible and near-infrared region, providing information on the photoinduced dynamics within the structure. We investigate multilayer stacks of (MEPE/PSS) that is, a metallofunctionalized polyelectrolyte-amphiphile multilayer complex fabricated by the layer-by-layer technique, as well as gold colloid particle strata separated by several PAH/PSS layers. We compare the results to investigations of equivalent crystalline solid state multilayer structures with dimensions on the nanometer length scale. We compare the generation and propagation of specific hypersound waves in the frequency range of 1 THz, which is given by the speed of sound in the respective material (∼2 nm/ps) and its artificial spatial layering period (∼2nm). The timescale of the expansion mode of the entire structure is measured to lie in the ∼20ps range.