Antimicrobial activity of Ag surfaces sputtered by magnetron sputtering

Ag nanoparticles were deposited on polyamide textiles by direct current magnetron sputtering with an Ag target. This kind of composite material is effective in bacterial inactivation due to the presence of silver. It has been observed that the morphology of composite materials was affected by many factors, such as sputtering power, working pressure, sputtering time, etc. In this study, these parameters were 20 W and 0·5 Pa respectively with different sputtering times. Through antibacterial test on Escherichia coli, it has been found that the shortest sputtering time leading to inactivation was 160 s. The results of X-ray diffraction implied the crystalline and uncrystalline kinds of Ag, which showed that the thickness of the Ag surface must be above a certain value to form crystals. X-ray photoelectron spectroscopy was used to analyse the surface atomic concentration and state. The result indicated that there were different kinds of sliver spaces on the polyamide textiles. According to this, the antibacterial mechanism of the composite materials was discussed.