Berlin 2018 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 9: Postersession I

BP 9.14: Poster

Montag, 12. März 2018, 17:30–19:30, Poster A

Polymer brushes in motion – measuring flow with nanometre resolution — •Jan Christoph Thiele, Sebastian Isbaner, Narain Karedla, Ingo Gregor, and Jörg Enderlein — III. Institute of Physics – Biophysics, Georg August University Göttingen, Germany

Polymer brushes are a versatile method to tailor surface properties. These include wetting behaviour, friction and interactions with colloids and biomolecules. Coating a surface with polymer brushes changes its hydrodynamic properties in a complex way. Experiments on brush coated capillaries showed an unexpected large flow reduction by the brush, while recent simulations are predicting a backflow within the brush layer.

Our aim is to measure how the brushes impact the flow at the surface and to verify the predicted backflow. For this, we will use fluorescence lifetime correlation spectroscopy (FLCS) in combination with metal induced energy transfer (MIET). FLCS enables a precise and non-invasive measurement of the flow speed, while MIET causes a modulation of the dye’s lifetime in close proximity to a gold surface underneath the brush. This modulation allow us to section the volume into different layers based on their lifetime. We will use a fluorescence dye dissolved in the liquid or the brush and measure the movement of the dye molecules and their distance from the gold surface. This way we can obtain a high resolution flow profile in the range of 0 to 100 nm distance to the surface.