Applied Surface Science, Vol.311, 749-752, 2014
Distinct surface hydration behaviors of boron-rich boride thin film coatings
In this work, the surface boron chemical states and surface hydration behaviors of the as-deposited and annealed boron-rich boride thin film coatings, including AlMgB14,TiB2 and AlMgB14-TiB2, were systematically studied by use of X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The XPS results indicate that boron at annealed AlMgB14 film surface can be oxidized; surprisingly, such oxidation does not lead to the formation of boric acid in ambient air. Instead, boric acid can be produced at the surface of annealed TiB2 film and AlMgB14-TiB2 film. It is shown, via the water contact angle measurements, that these boride films exhibit distinct surface wettability characteristics, which are believed to result in the observed surface hydration processes. Furthermore, we found anatase TiO2 formation plays a major role in the surface wetting behaviors for these boride films. (C) 2014 Elsevier B.V. All rights reserved.