Lecture
Van Marum Colloquium: Influence of Nanoscale Surface Topography and Chemical Modification on Electrical Double-Layer Interactions in Aqueous Media
- Date
- Tuesday 10 February 2026
- Time
- Location
-
Gorlaeus Building
Einsteinweg 55
2333 CC Leiden - Room
- GM.4.13
Abstract
Electrical double-layer (EDL) interactions play a crucial role in electrochemical and interfacial phenomena, as they are highly sensitive to surface properties. However, real electrode surfaces are inherently rough and chemically heterogeneous. In aqueous solutions, EDL interactions coexist with dispersion (van der Waals) forces.
Here, the influence of nanoscale surface topography and surface chemical modification via self-assembled monolayers (SAMs) on EDL interactions is quantified. Atomic Force Microscopy (AFM) force measurements are performed between gold surfaces with controlled nanoscale roughness, as well as between hydrophilic gold and hydrophobically modified alkanethiol SAM surfaces, in deionized water and weakly salted electrolytes. The force profiles are interpreted by solving the nonlinear Poisson–Boltzmann equation for realistic surface geometries under constant-potential boundary conditions, enabling the extraction of key EDL parameters such as the Debye screening length and effective surface potentials. The results demonstrate that nanoscale roughness and surface chemistry can substantially modify the magnitude and effective range of EDL interactions. These findings highlight the importance of accounting for realistic surface morphology and chemical modification when probing and modeling electrical double layers at electrochemical interfaces.