Metal-containing amorphous carbon films for hydrophobic application

Tetrahedral amorphous carbon (ta-C) and metal-containing amorphous carbon (a-C/Me) films including a-C/Ni, a-C/Fe and a-C/Al films were deposited using metal-carbon composite targets, by a filtered cathodic vacuum arc (FCVA) technique. The wettability of the films was examined by the contact angle measurement. Three types of liquid with different polarity were used to study the changes in the surface energy including the dispersive and polar components. Micro-Raman spectroscopy and X-ray induced photoelectron spectroscopy were used to characterize the structural and surface properties of the films. Atomic force microscopy (AFM) was used to characterize the morphology and roughness of the films. The contact angle decreases after incorporating Ni into the films. However, the contact angle of films increases after incorporating Fe and Al into the films, respectively. The contact angle of a-C/Al film with water reaches as high as 104°. The roughness of the films has no obvious effect on the contact angle. The structure and surface analysis show that the surface energy is related to sp3/sp2content in the film. The surface adsorption plays an important role in the change of the surface energy.