Ion adsorption at mineral-electrolyte interfaces
Event details
| Date | 29.10.2015 |
| Hour | 10:00 |
| Speaker | Prof. Frieder Mugele, University of Twente |
| Location | |
| Category | Conferences - Seminars |
From atomic scale AFM imaging to macroscopic wetting transitions
The distribution of ions and charge at solid-water interfaces plays an essential role in a wide range of processes in biology, geology and technology. While theoretical models of the solid-electrolyte interface date back to the early 20th century, experimental techniques largely rely on macroscopic averaging and therefore lack the spatial resolution to test key predictions.
Using recent advances in high-resolution Atomic Force Microscopy (AFM) we show, with atomic level precision, how cations common in natural environments adsorb to heterogeneous mineral-electrolyte interfaces and thereby alter the electrostatic and chemical properties of the surface. In combination with density functional theory calculations, the experiments reveal a detailed picture of the formation of surface phases by templated adsorption of ions under the influence of electrostatic and hydration forces.
These changes of the microscopic surface chemistry have dramatic consequences for the affinity of organic solutes and in particular for the macroscopic wettability of the surfaces: mica surfaces immersed in ambient decane, display a transition from complete water wetting to partial wetting. This transition is controlled by the affinity of the cations to the interface that can be described by a Hofmeister series of wettability. This phenomenon is believed to play a major role in the success of modern technologies of enhanced oil recovery.
Bio: Prof. Mugele studied physics at the University of Konstanz (Germany) and obtained his PhD there in 1997 with a work in surface science studying diffusion on metal surfaces in ultrahigh vacuum. During a postdoctoral research stay (1998/99) as a Humboldt Fellow at the Lawrence Berkeley National Laboratory in Berkeley, CA (USA) he became interested in liquid-solid interfaces and confined liquids. As a research assistant at the University of Ulm (Germany; 1999-2004; habilitation 2003), he extended his work to wetting of functionalized surfaces, including in particular electrowetting. Since 2004, he has been full Professor of Physics of Complex Fluids at the University of Twente (The Netherlands).
Prof. Mugele is heading a group of approx. 25 researchers studying fundamental and applied aspects of fluids at interfaces on scales ranging from molecular dimensions to the millimeter scale. Prof. Mugele’s research interest include electrowetting, wetting of complex surfaces, dynamic wetting, drop dynamics, two-phase flow microfluidics, AFM spectroscopy in fluids, confined liquids, nanofluidics, optofluidics, colloids, (micro-)rheology. Application areas include inkjet printing, immersion lithography, lab-on-a-chip systems – and in particular enhanced oil recovery.
Prof. Mugele has published more than 140 scientific articles including the standard review on electrowetting.
The distribution of ions and charge at solid-water interfaces plays an essential role in a wide range of processes in biology, geology and technology. While theoretical models of the solid-electrolyte interface date back to the early 20th century, experimental techniques largely rely on macroscopic averaging and therefore lack the spatial resolution to test key predictions.
Using recent advances in high-resolution Atomic Force Microscopy (AFM) we show, with atomic level precision, how cations common in natural environments adsorb to heterogeneous mineral-electrolyte interfaces and thereby alter the electrostatic and chemical properties of the surface. In combination with density functional theory calculations, the experiments reveal a detailed picture of the formation of surface phases by templated adsorption of ions under the influence of electrostatic and hydration forces.
These changes of the microscopic surface chemistry have dramatic consequences for the affinity of organic solutes and in particular for the macroscopic wettability of the surfaces: mica surfaces immersed in ambient decane, display a transition from complete water wetting to partial wetting. This transition is controlled by the affinity of the cations to the interface that can be described by a Hofmeister series of wettability. This phenomenon is believed to play a major role in the success of modern technologies of enhanced oil recovery.
Bio: Prof. Mugele studied physics at the University of Konstanz (Germany) and obtained his PhD there in 1997 with a work in surface science studying diffusion on metal surfaces in ultrahigh vacuum. During a postdoctoral research stay (1998/99) as a Humboldt Fellow at the Lawrence Berkeley National Laboratory in Berkeley, CA (USA) he became interested in liquid-solid interfaces and confined liquids. As a research assistant at the University of Ulm (Germany; 1999-2004; habilitation 2003), he extended his work to wetting of functionalized surfaces, including in particular electrowetting. Since 2004, he has been full Professor of Physics of Complex Fluids at the University of Twente (The Netherlands).
Prof. Mugele is heading a group of approx. 25 researchers studying fundamental and applied aspects of fluids at interfaces on scales ranging from molecular dimensions to the millimeter scale. Prof. Mugele’s research interest include electrowetting, wetting of complex surfaces, dynamic wetting, drop dynamics, two-phase flow microfluidics, AFM spectroscopy in fluids, confined liquids, nanofluidics, optofluidics, colloids, (micro-)rheology. Application areas include inkjet printing, immersion lithography, lab-on-a-chip systems – and in particular enhanced oil recovery.
Prof. Mugele has published more than 140 scientific articles including the standard review on electrowetting.
Practical information
- General public
- Free
Organizer
- Francesco Stellacci <francesco.stellacci@epfl.ch>
Contact
- Quy Ong <quy.ong@epfl.ch>