The microstructure evolution and the excellent hydrophilicity of self-grown Ag particles/Ag-W alloy films

Abstract

Ag-W hydrophilic alloy films with different W contents were prepared on soda-lime glass substrates by magnetron sputtering. The effects of W content and film thickness on the microstructure, wettability and the surface energy of Ag-W alloy films were discussed in detail. It is found that the addition of W atoms facilitates the formation of polyhedral Ag nanoparticles on the surface of Ag-W alloy films. Furthermore, as the W content increases, the number of Ag nanoparticles on the surface increases. Atomic force microscopy analysis shows that the surface roughness of the film increases gradually with the increase of W content. It is worth noting that the water contact angle(WCA) of the Ag-78.68 at% W film is only 21.32° due to the rougher surface and the higher surface energy, which is significantly lower than that of pure Ag films and other metal films. In addition, the surface morphology of the alloy film changed significantly with the increase of film thickness, which affected the hydrophilicity. This work provides a straightforward and economical method to prepare hydrophilic alloy films.