Berlin 2005 – scientific programme
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AKB: Biologische Physik
AKB 60: Membranes and Vesicles
AKB 60.4: Talk
Tuesday, March 8, 2005, 16:45–17:00, TU H2013
Collective Dynamics of Lipid Membranes studied by Inelastic Neutron Scattering — •Maikel Rheinstädter1, Tilo Seydel1, Wolfgang Häussler2, and Tim Salditt3 — 1Institut Laue-Langevin, 6 rue Jules Horowitz, B.P. 156, 38042 Grenoble, France — 2FRM II, Lichtenbergstrasse 1, 85747 München, Germany — 3Institut für Röntgenphysik, Geiststrasse 11, 37037 Göttingen, Germany
While most spectroscopic techniques, as e.g. nuclear magnetic resonance or dielectric spectroscopy, are limited to the center of the Brillouin zone and probe the macroscopic response, inelastic neutron and X-ray scattering experiments give the unique access to microscopic dynamics at length scales down to intermolecular distances. Only recently, it has become possible to study collective dynamics of planar lipid bilayers using neutron spectroscopy techniques [1]. We determined the dispersion relations in the gel and in the fluid phases of a DMPC model membrane and could shed light on the evolution of structure and dynamics and the relation between them in the range of the gel-fluid main phase transition. Here, the scattering volume restriction for inelastic neutron experiments was overcome by stacking several thousand highly aligned membrane bilayers. By combining neutron triple-axis, backscattering and spin-echo spectroscopy, we present measurements of short and long wavelength collective fluctuations in biomimetic and biological membranes in a large length and energy range. A recent backscattering study for the first time gave access to the dynamics of the ”membrane-water”, i.e. the water layer in between the stacked membranes.
[1] M.C. Rheinstädter et al., Phys. Rev. Lett. 93, 108107 (2004).