Special MechE Colloquium: A water window on complex surfaces
Event details
| Date | 14.05.2020 |
| Hour | 16:00 › 17:00 |
| Speaker | Prof. Sylvie Roke, Laboratory for fundamental BioPhotonics, School of Engineering, Interschool Institute of Bioengineering, EPFL |
| Location | |
| Category | Conferences - Seminars |
Abstract:
Chemical surface reactions and transformations at solid/liquid interfaces depend strongly on the local electrostatic interfacial environment as well as on nano- and microscale structures, structural heterogeneities, and confinement. Characterizing these processes is a challenge and fundamental interface characterization is traditionally done on well-defined planar model systems. How far such studies still are from providing molecular level information from realistic systems is a relevant question both from a fundamental and technological perspective. Here I will present advancements in nonlinear optical technology as a solution that allows the characterization of not only interfacial structure, but also dynamics as well as the quantification of electrostatic potential landscapes in real time and space using water as a probe. I will focus on wide-field second harmonic (SH) microscopy to image in 3D and on millisecond time scales the interfacial structure, surface potential and dynamics of the curved inside of a water/glass micro-capillary interface. We provide real time information about the local chemical environment and derive electrostatic surface potential maps as well as real-time spatially resolved surface acid dissociation constant pKa,s values for the silica deprotonation reaction. Finally, we conclude that although mean field models can provide insights into the behavior of complex interfaces, they only do so when the time and length scales of the probes are long enough.
Bio:
Sylvie Roke is a full professor at EPFL. She obtained master degrees in chemistry (2000) and physics (2000) from Utrecht University (NL) with highest honors, and then obtained a PhD degree (2004, highest honors) from Leiden University with AW Kleyn and M Bonn. She was Max-Planck free floating Group Leader at the MPI for Metals Research in Stuttgart (2006-2012), and became director of the Laboratory for fundamental BioPhotonics at EPFL in 2011, where she holds the Julia Jacobi chair in photomedicine. Her work focuses on developing new optical tools and theories for gaining molecular level insight into aqueous systems and interfaces. She applies them to understand water, aqueous solutions, realistic interfaces and biological systems. She was awarded the LJ Oosterhoff prize (2003), the Minerva prize (2006), the Hertha-Sponer prize (2008), as well as ERC Startup (2009), Consolidator (2014) and Proof of Concept (2020) grants.
Chemical surface reactions and transformations at solid/liquid interfaces depend strongly on the local electrostatic interfacial environment as well as on nano- and microscale structures, structural heterogeneities, and confinement. Characterizing these processes is a challenge and fundamental interface characterization is traditionally done on well-defined planar model systems. How far such studies still are from providing molecular level information from realistic systems is a relevant question both from a fundamental and technological perspective. Here I will present advancements in nonlinear optical technology as a solution that allows the characterization of not only interfacial structure, but also dynamics as well as the quantification of electrostatic potential landscapes in real time and space using water as a probe. I will focus on wide-field second harmonic (SH) microscopy to image in 3D and on millisecond time scales the interfacial structure, surface potential and dynamics of the curved inside of a water/glass micro-capillary interface. We provide real time information about the local chemical environment and derive electrostatic surface potential maps as well as real-time spatially resolved surface acid dissociation constant pKa,s values for the silica deprotonation reaction. Finally, we conclude that although mean field models can provide insights into the behavior of complex interfaces, they only do so when the time and length scales of the probes are long enough.
Bio:
Sylvie Roke is a full professor at EPFL. She obtained master degrees in chemistry (2000) and physics (2000) from Utrecht University (NL) with highest honors, and then obtained a PhD degree (2004, highest honors) from Leiden University with AW Kleyn and M Bonn. She was Max-Planck free floating Group Leader at the MPI for Metals Research in Stuttgart (2006-2012), and became director of the Laboratory for fundamental BioPhotonics at EPFL in 2011, where she holds the Julia Jacobi chair in photomedicine. Her work focuses on developing new optical tools and theories for gaining molecular level insight into aqueous systems and interfaces. She applies them to understand water, aqueous solutions, realistic interfaces and biological systems. She was awarded the LJ Oosterhoff prize (2003), the Minerva prize (2006), the Hertha-Sponer prize (2008), as well as ERC Startup (2009), Consolidator (2014) and Proof of Concept (2020) grants.
Practical information
- General public
- Free