title: Evidence for phase separation of ethanol-water mixtures at the hydrogen terminated nanocrystalline diamond surface.
abstract: Interactions between ethanol-water mixtures and a hydrophobic hydrogen terminated nanocrystalline diamond surface, are investigated by sessile drop contact angle measurements. The surface free energy of the hydrophobic surface, obtained with pure liquids, differs strongly from values obtained by ethanol-water mixtures. Here, a model which explains this difference is presented. The model suggests that, due to a higher affinity of ethanol for the hydrophobic surface, when compared to water, a phase separation occurs when a mixture of both liquids is in contact with the H-terminated diamond surface. These results are supported by a computational study giving insight in the affinity and related interaction at the liquid-solid interface.
authors.affiliation: Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, 3590 Diepenbeek, Belgium. stoffel.janssens@uhasselt.be
authors.forename: Stoffel D
authors.initials: SD
authors.lastname: Janssens
authors.forename: Sien
authors.initials: S
authors.lastname: Drijkoningen
authors.forename: Marc
authors.initials: M
authors.lastname: Saitner
authors.forename: Hans-Gerd
authors.initials: HG
authors.lastname: Boyen
authors.forename: Patrick
authors.initials: P
authors.lastname: Wagner
authors.forename: Karin
authors.initials: K
authors.lastname: Larsson
authors.forename: Ken
authors.initials: K
authors.lastname: Haenen
mesh_terms: D018130:Diamond / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D000431:Ethanol; D018130:Diamond; D006859:Hydrogen