title: Suppression of Hydrophobic Recovery by Plasma Polymer Films with Vertical Chemical Gradients.
abstract: Vertical chemical gradients extending over a few nanometers were explored. The gradients are based on plasma-polymerized oxygen-containing ethylene (ppOEt) films. Using plasma conditions with low CO2/C2H4 ratio and high energy input, cross-linked films were deposited as base layer, while increasing CO2 and lowering energy input resulted in less cross-linked yet highly functional films as applied as top layer. Aging studies indicate that, in particular, for very thin gradient structures, the cross-linked subsurface zone effectively hinders reorientation of the surface functional groups, thus restricting hydrophobic recovery and oxidation effects.
authors.affiliation: Laboratory of Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology, Empa , Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hegemann
authors.affiliation: Laboratory of Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology, Empa , Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.|Department of Chemistry, University of Bari , Via Orabona 4, 70126 Bari, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Lorusso
authors.affiliation: Laboratory of Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology, Empa , Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
authors.forename: Maria-Isabel
authors.initials: MI
authors.lastname: Butron-Garcia
authors.affiliation: Laboratory of Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology, Empa , Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
authors.forename: Noémi E
authors.initials: NE
authors.lastname: Blanchard
authors.affiliation: Laboratory of Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology, Empa , Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Rupper
authors.affiliation: Department of Chemistry, University of Bari , Via Orabona 4, 70126 Bari, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Favia
authors.affiliation: Laboratory of Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology, Empa , Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
authors.forename: Manfred
authors.initials: M
authors.lastname: Heuberger
authors.affiliation: Laboratory of Advanced Fibers, Swiss Federal Laboratories for Materials Science and Technology, Empa , Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
authors.forename: Marianne
authors.initials: M
authors.lastname: Vandenbossche