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AKB: Biologische Physik
AKB 2: Membranes: Conformations and Dynamics
AKB 2.3: Vortrag
Montag, 27. März 2006, 11:00–11:15, ZEU 260
Collective dynamics of lipid membranes studied by inelasticneutron scattering — •Maikel C. Rheinstädter1, Tilo Seydel1, Wolfgang Häußler2, and Tim Salditt3 — 1Institut Laue-Langevin,B.P. 156,6 rue JulesHorowitz,38042 Grenoble,France — 2FRM-II,Technische Universität München,85747Garching,Germany — 3Institut für Röntgenphysik,Friedrich-Hund-Platz1,37077 Göttingen,Germany
While most spectroscopic techniques, as ,e.g., nuclear magnetic resonance or dielectric spectroscopy probe macroscopic responses, neutron and within some restrictions also x-ray scattering experiments give the unique access to microscopic dynamics at length scales of intermolecular distances. Only recently, it has become possible to study collective dynamics, ,i.e., the dispersion relations in the gel and fluid phases of planar lipid bilayers using neutron spectroscopy techniques[1]. By combining neutron three-axis, backscattering and spin-echo spectroscopy, we present measurements of short and long wavelength collective fluctuations in a biological model membrane in a large range in momentum and energy transfer, covering time scales from about 0.1 ps to almost 1 µs and length scales from 3 Å to about 1000 Å. Neutron backscattering technique thereby gives information about molecular dynamics of lipid acyl chains and the water molecules in between the stacked bilayers [2]. The dispersion relation of the long wavelength undulation modes has been determined by quasielastic reflectometry using spin-echo spectrometers.
[1] M.C. Rheinstädter et al., Phys. Rev. Lett. 93, 108107 (2004).
[2] Maikel C. Rheinstädter et al., Phys. Rev. E 71, 061908 (2005).