Employing cold atmospheric plasma (Ar, He) on Ag thin flm and their infuences on surface morphology and anti‑bacterial activity of silver flms for water treatment

In this work to investigate the efects of using diferent gases in cold atmospheric plasma (CAP) on surface treatment of silver thin flms (100, 120 nm flm thickness) He and Ar were employed. Ag was sputtered on glass substrate and X-ray difraction (XRD) as well as atomic force microscopy (AFM) for structural and morphological studies before and after plasma radiation was carried out. Surface treatment of Ag thin flms by CAP increased surface roughness especially with Ar plasma, this rise of surface roughness of Ag thin flm leads to make their surface hydrophilic which can be very important for antibacterial activity of Ag flms in removal of Escherichia coli (E. coli) which was used as target bacterium. Argon plasma radiation was more efective than helium on both surface morphology and anti-bacterial property. XRD results showed that crystalline orientation of [111] peak of silver remains as preferred orientation, but the grain size did not change that much after plasma treatment. The crystalline size was calculated by Debye–Scherrer formula using peak [111] of Ag samples (as the most intense peak of silver).