title: Surface modifications using a water-stable silanetriol in neutral aqueous media.
abstract: Surface modifications of glass slides employing the sterically hindered tert-butyl substituted silanetriol are described. To the best of our knowledge, this is the first time that a stable silanetriol has been directly used for this purpose. So far unprecedented, this process runs under neutral aqueous conditions and in the absence of organic solvents, which makes coating protocols accessible to acid-sensitive substrates. The layer thickness and surface topography are investigated by the Sarfus technique, by X-ray reflectivity, and by atomic force microscopy (AFM). These techniques yield values of 0.8±0.1 (XRR) and 0.6±0.2 nm (Sarfus) for layer thickness and 0.33 nm for root mean square roughness (AFM). The modified surfaces have hydrophobic and oleophilic character and contact angles (CA) between 60° (formamide, CH2I2) and 90° (water) are obtained. The thin coatings allow a structuring by UV/ozone treatment in order to get hydrophilic and hydrophobic compartments on the surfaces. For all coatings, surface free energies are calculated using different models. To determine the isoelectric points (IEP) of the modified surfaces, we performed zeta-potential measurements. Correlations between zeta potentials and hydrophilicity of the surfaces are shown.
authors.affiliation: Institut für Chemie, Karl-Franzens-Universität Graz, Heinrichstrasse 28/IV, 8010 Graz, Austria. stefan.spirk@uni-graz.at
authors.forename: Stefan
authors.initials: S
authors.lastname: Spirk
authors.forename: Heike M
authors.initials: HM
authors.lastname: Ehmann
authors.forename: Rupert
authors.initials: R
authors.lastname: Kargl
authors.forename: Natascha
authors.initials: N
authors.lastname: Hurkes
authors.forename: Martin
authors.initials: M
authors.lastname: Reischl
authors.forename: Jiri
authors.initials: J
authors.lastname: Novak
authors.forename: Roland
authors.initials: R
authors.lastname: Resel
authors.forename: Ming
authors.initials: M
authors.lastname: Wu
authors.forename: Rudolf
authors.initials: R
authors.lastname: Pietschnig
authors.forename: Volker
authors.initials: V
authors.lastname: Ribitsch