Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 2: Focus: Amphiphilic Systems II

CPP 2.3: Vortrag

Montag, 23. März 2009, 15:00–15:15, ZEU 222

Dissolution of amphiphiles: a time- and space-resolved study — •Helen E Hermes and Stefan U Egelhaaf — Physik der weichen Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf

Amphiphiles in solution can self-assemble into a variety of structures. Due to their molecular architecture, lipids and non-ionic surfactants tend to form lamellae over a wide range of sample conditions. Upon contact with water these stacks of bilayers swell due to the influx of the water. During this non-equilibrium dissolution process fascinating interface instabilities, so-called myelins, may be observed. To date, information about how such interfacial instabilities form and grow has been obtained using optical techniques. Recently, it has become possible to quantitatively determine the evolution of the microscopic concentration profiles using neutron imaging. Due to latest technical improvements in this method, time- and space-resolved water profiles can now be determined in-situ. In this presentation, an overview of current understanding of the dissolution of amphiphiles and the formation of non-equilibrium structures will be given. Particular emphasis will be placed on the new quantitative data obtained using neutron imaging and the knowledge gained by a comparison with computer simulations of the processes occurring during amphiphile dissolution.