Tailoring the wettability of nanocrystalline TiO2 films

The atmospheric pressure glow discharge burning in argon with small admixture of oxygen and hexamethyldisiloxane is used for the deposition of organosilicon and SiOx-like films on the stainless steel surface. The organosilicon film has high growth rate (85 nm/min) and extremely low surface roughness (0.8 nm), while the SiOx-like film shows relatively low growth rate (40 nm/min) and higher surface roughness (9 nm). The surface wettability, microhardness and the corrosion resistance of the deposited siloxane films are detected. The organosilicon film is hydrophobic (contact angle: 98 degrees) and soft (microhardness: 0.68 GPa), while the SiOx-like film is hydrophilic (contact angle: 45 degrees) and hard (microhardness: 7.85 GPa). The potentiodynamic polarization tests show that by depositing siloxane films on the surface, the corrosion resistance of the stainless steel in the Hanks solution can be largely improved. In particular, the SiOx-like film exhibits better corrosion resistance than the organosilicon film. (C) 2011 Elsevier B.V. All rights reserved.