title: Response of Plasma-Polymerized Hexamethyldisiloxane Films to Aqueous Environments.
abstract: Thin plasma polymer films were deposited in hexamethyldisiloxane (HMDSO) and HMDSO/O2 low-pressure discharges and their chemical structures analyzed using infrared (IR) spectroscopy and neutron reflectometry (NR). The (plasma-polymerized) ppHMDSO film exhibits hydrophobic, poly(dimethylsiloxane)-like properties, while the retention of carbon groups is reduced by O2 addition, yielding a more inorganic, hydrophilic ppSiOx film. Both films show a minor (vertical) density gradient perpendicular to the substrate, where the exposed film surface seems to be more oxidized, indicating oxidative aging reactions upon contact with air. The hydration and water uptake abilities of the films in aqueous environments were investigated in humid environments using ellipsometry, NR in D2O, and multiple transmission-reflection IR measurements after equilibration of the films in water.
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology , 9014 St. Gallen, Switzerland.|Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich , 8093 Zürich, Switzerland.
authors.forename: Noemi E
authors.initials: NE
authors.lastname: Blanchard
authors.affiliation: Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich , 8093 Zürich, Switzerland.
authors.forename: Vikrant V
authors.initials: VV
authors.lastname: Naik
authors.affiliation: Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut , 5232 Villigen, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Geue
authors.affiliation: Fraunhofer Research Institution for Polymeric Materials and Composites PYCO , 14513 Teltow, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Kahle
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology , 9014 St. Gallen, Switzerland.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hegemann
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology , 9014 St. Gallen, Switzerland.|Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich , 8093 Zürich, Switzerland.
authors.forename: Manfred
authors.initials: M
authors.lastname: Heuberger
mesh_terms: D058105:Polymerization; D012833:Siloxanes / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D014867:Water / Q000737:chemistry*
chemical_list: D012833:Siloxanes; D014867:Water; C015917:hexamethyldisiloxane