A comparative study of the structure and chemical properties of nanocomposite TiCaPCON-Ag coatings

Abstract

To induce antibacterial activity in bioactive TiCaPCON coatings, materials have been doped with Ag in a quantity of 0.4–4.0 at %. Silver has been introduced into the coatings via two methods. Coatings with 0.4, 1.2, and 4.0 at % Ag content have been fabricated via simultaneous sputtering of a compositional TiC0.5-Ca3(PO4)2 target, which was obtained via self-propagating high temperature synthesis, and of a metallic Ag target. TiCaPCON-Ag (4.0 at %) coating was also fabricated via ion Ag implantation of preliminarily obtained TiCaPCON. The content and element distribution over the thickness of the coating were studied via glow discharge optical emission spectroscopy (GD-OES). The structure and morphology of the coatings have been probed via scanning electron microscopy. The results showed the formation of Ag particles in both the bulk and on the surface of the coatings, but their size and distribution over the coating thickness are found to depend on both the Ag concentration and method of sputtering of coatings. The effect of substrate temperature on Ag particle distribution in the coating is established. The study of kinetics of Ag dissolution via inductively coupled plasma mass-spectrometry and electrochemical methods has revealed that Ag dissolution rate is defined by the ratio of Ag nanoparticle size to the thickness of an oxide layer on the surface.