Berlin 2001 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 18: Poster: Polymer Blends, Heterogeneous Systems, Colloids and Nanoparticles, Interfaces, Polyelectrolytes

CPP 18.31: Poster

Wednesday, April 4, 2001, 12:30–15:00, AT1

Diffusion of Phospholipids coupled to Polyelectrolyte Multilayers: A Fluorescence Recovery Study — •Liying Wang, Monika Schönhoff, and Helmuth Möhwald — Max-Planck Institute of Colloids and Interfaces, D-14424 Potsdam/Golm

Coupled systems of polyelectrolyte and lipid monolayers are model systems for biological membranes. To investigate the strength of binding between synthetic phospholipids and multilayers of polyelectrolytes, here FRAP (Fluorescence Recovery After Photobleaching) is applied: The lateral diffusion coefficient D of dye-labelled lipids is determined from the lateral decay of an interference pattern previously photobleached into the film. Diffusion coefficients are determined for zwitterionic or ionic lipid head groups; and for zwitterionic head groups coupled to polyelectrolyte layers of different charge. The coupling strength is apparently similar in all these systems, since the lipid head group has a sufficiently large mobility to optimize the interaction with the polymer charges. In dependence of temperature diffusion coefficients are strongly varying and show an Arrhenius type behaviour where the activation energy for the diffusion process is extracted.