Research Training Group 2154 - Materials for Brain

Svenja Hövelmann

Fast and ultrafast Dynamics of Liquid Interfaces

Understanding and controlling structure and function of liquid interfaces is a constant challenge in biology, nanoscience and nanotechnology, with applications ranging from molecular electronics to controlled drug release. X-ray reflectivity and grazing incidence diffraction provide an invaluable probe for studying the atomic scale structure at liquid–air interfaces. The work will be centered at the ultra-fast laser system at the LISA diffractometer situated at beamline P08 at the PETRA III synchrotron radiation source in Hamburg. The femtosecond laser at our LISA diffractometer at PETRA III allows unique opportunities to investigate photo-induced structural changes at liquid interfaces on the pico-and nanosecond time scales with pump-probe techniques. This PhD will concentrate on the study of solvation at the water/air interface, the non-equilibrium dynamics of capillary waves, local order in molecular model layers and photoinduced dynamic processes in biophysical model systems. One part of this PhD concentrates on understanding the interaction of the membrane and its components. This will allow the design of a controllable membrane structure and with it a controlled release of enclosed particles. For that vesicles made of the lipids used previously to form the membrane will be made and then characterised and investigated in terms of their size, shape and the changes induced by illumination of the vesicles. Different technics such as Small Angle X-ray Scattering (SAXS) and Diffuse Light Scattering (DLS) will be used. Depending on the results of the response of the membrane due to the illumination the composition of the vesicles will be adapted and optimised. This is mandatory to understand the mechanisms for a future application as a local drug release within the human body.