Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 2: Focus: Amphiphilic Systems II

CPP 2.1: Hauptvortrag

Montag, 23. März 2009, 14:00–14:30, ZEU 222

Structure transformations in surfactant bilayer systems — •Olsson Ulf — Div. of Physical Chemistry Lund University Box 124 SE-221 00 Lund, Sweden

Surfactants and lipid bilayers in solution may form closed shells as in vesicles, planar films as in lamellar phases or multiply connected or branched films as in the sponge phases. Structural transformations between these different topologies involves the fusion or fission of bilayer films. Bilayer fusion and fission are also important biological events, like in endocytosis and exocytosis, and it is of some interest to study these processes in more simple surfactant model systems. Using non-ionic surfactants, where structural transformations are conveniently triggered by small temperature changes, we have studied kinetics in a sponge phase and the kinetics of a lamellar-sponge phase transition. In another study we have focused on vesicle stability. Since Ostwald ripening like processes in these systems are very slow and may be anti-coarsening, vesicle dispersions may have a very long shelf-life if vesicle fusion is a rare event. Vesicle stability depends on the surfactant monolayer spontaneous curvature.