Microstructure and properties of Ag/N dual ions implanted titanium

Silver (Ag) and nitrogen (N) dual ions were sequentially implanted into titanium to prepare the samples including PIII-Ag–N (Ag ions prior to N implantation), PIII-N–Ag (N prior to Ag ions implantation) and PIII-Ag + N (Ag/N dual ions co-implantation) via plasma immersion ion implantation (PIII) technology. All of the samples were characterized by a scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The antibacterial activity, corrosion resistance and hardness of as-implanted samples were investigated. The results show that the Ag/N dual ions implanted titanium exhibit high bactericidal ability to Escherichia coli and Staphylococcus aureus due to the formation of silver nanoparticles in the near surface region. The zeta potentials show more positive evolution in order of pure titanium, PIII-Ag–N, PIII-N–Ag and PIII-Ag + N, which favors to contact with bacteria thus to inhibit their growth and proliferation. Moreover, the formation of titanium nitride layer during Ag/N dual ions implantation can greatly improve the corrosion resistance and hardness of titanium. The present study suggests that the Ag/N dual ions co-implanted process is the most efficient way to obtain the titanium implant with high antibacterial activity, corrosion resistance and hardness.

Research highlights
► Ag/N dual ions were implanted into Ti in different sequence using PIII.
► Ag nanoparticles appeared on the surface of Ag/N dual ions implanted Ti.
► Ag/N dual ions co-implanted Ti exhibited high antibacterial activity.
► Ag/N dual ions implantation improved the corrosion resistance and hardness of Ti.