Lieber Veranstalterin, bitte denken Sie aus Gründen des Datenschutzes daran, dass die von Ihnen für die jeweilige Veranstaltung nicht mehr benötigten Teilnehmerlisten, sonstige Dokumente etc. gelöscht werden müssen. Vielen Dank.

8.–10. Nov. 2021
University of Freiburg
Europe/Berlin Zeitzone

Energy harvesting due to charge redistribution upon drop impact & Swelling of partly saturated hydrophobic polymer brush layers

08.11.2021, 16:00
45m
Aula, Kollegiengebäude I (University of Freiburg)

Aula, Kollegiengebäude I

University of Freiburg

Platz der Universität 3, 79098 Freiburg
Keynote

Sprecher

Frieder Mugele (Physics of Complex Fluids, University of Twente)

Beschreibung

The first part of this lecture I discuss how the energy of falling drops impacting onto pre-charged hydrophobic polymer surfaces can be harvested in an external electrical circuit as screening charges redistribute within the drop.
High speed video imaging and simultaneous electrical measurements lead to a physical model of the energy conversion process including a quantitative analysis of the conversion efficiency [1, 2].
Part two addresses preliminary experiments on the spreading of oil drops with a low vapor pressure on hydrophobic polymer brushes. Within a few hours the swelling process leads to the formation of a pronounced halo around the macroscopic contact line, where the thickness of the partially swollen brush layer varies by a few hundred nanometers over a lateral width of the order of 1mm. The experiments suggest that this seemingly static configuration is in fact stabilized by a very slow gradual evaporation and therefore intrinsically a non-equilibrium phenomenon.

[1] Wu, H., et al., Energy Harvesting from Drops Impacting onto Charged Surfaces. Physical Review Letters, 2020. 125: 078301.
[2] Wu, H., et al., Charge Trapping-Based Electricity Generator (CTEG): An Ultrarobust and High Efficiency Nanogenerator for Energy Harvesting from Water Droplets. Advanced Materials, 2020. 32: 2001699.

Hauptautor

Frieder Mugele (Physics of Complex Fluids, University of Twente)

Präsentationsmaterialien

Es gibt derzeit keine Materialien.