Probing the wetting properties of solid-liquid interfaces

NAISS 2024/5-275


NAISS Medium Compute

Principal Investigator:

Lorenzo Agosta


Uppsala universitet

Start Date:


End Date:


Primary Classification:

10402: Physical Chemistry




AIM AND TASK: This project will make use of classical and ab-initio molecular dynamics simulations to probe the wettability of solid surfaces. TiO2 and CeO2 interfaces with varying protonation state will be used.. CONTEXT: Water-metal-oxide interfaces play decisive roles in a range of vital applications such as photoelectrochemical energy conversion, nanotoxicology, biosensing and energy storage (e.g. Li-ion batteries). To understand and tailor the structure and functionality of such interfaces is therefore of prime interest. One key aspect is the structure of water molecules in the proximity of nanosurfaces (say, within 1 nm) that mediate the interaction with the surrounding environment. Probing minute amounts of adsorbed surface water species in the presence of significant excess of a bulk water phase represents a serious challenge for experimental approaches, due to the dispersion of the interfacial signal with respect to the bulk liquid phase. Relatively few attempts to probe metal-oxide surfaces directly in aqueous environments have been reported so far. These include studies by inelastic and quasi-elastic neutron scattering, atomic force microscopy and sum frequency generation. Although these studies indicate the existence of a layer of constrained water molecules exhibiting limited mobility at the nanoparticle perimeter, no further information on structure and speciation within that layer could be elucidated. This is a very challenging field in strong development. In our recent publication ( we demonstrated that the structure of water in the first adsorbed layer on metal oxides can induce hydrophobicity. This effect can be exploited to tailoring wetting properties and adsorption of organic molecules as in liquid chromatography techniques. We showed that hydrophobicity can be assessed by the interfacial water diffusion. Hence we will extend the study of diffusion regimes for water in close contact with meta-oxide surfaces in order to grasp their wetting properties under different pH environments. This project is now funded by VR international post-doc granted by me for the period 2022-2025.