Water and ions at interfaces

Experiments and simulations show that water at hydrophobic substrates forms a few Angstrom-thick vacuum layer. The top water layer is oriented, giving rise to a sizeable dipole moment and thus a potential drop, favoring the adsorption of negative ions. Ab-initio quantum chemistry methods allow to calculate the interactions between ions and ionic properties such as ionization potentials and polarizabilities, important for the prediction of ionic interfacial density profiles.