Final Activity Report Summary - FAB-HETERO-COATS (Fabrication of Novel Heterophase ta-C: Me Nanocomposite Coatings for Biomedical Applications)
We studied biocompatible diamond-like carbon (DLC) coatings that were manufactured using a novel plasma ion immersion implantation and deposition (PIIID) technique. We manufactured novel biocompatible coatings based on DLC and alloyed it with silver, which was known to have a strong antibacterial efficacy. Samples with different concentrations of the alloying element were prepared. In this study, we also compared the biocompatibility and mechanical properties of nanocomposite of the prepared hydrogenated and hydrogen-free DLC-Ag coatings using two different deposition techniques:
1. dual cathode pulsed cathodic-arc (PCA) from silver and graphite cathodes; and
2. Ag cathodic-arc in reactive methane (CH4) atmosphere.
Moreover, we examined the formation of nanocomposite films which were formed when different metals such as Mo, Au, Ag, or Cu were inserted into a carbon host matrix. A novel 'selective bias' filter-cathodic-arc deposition method that allowed the co-deposition of C and various metal ions without creating heavy-ion damage and re-sputtering was used for this purpose. The addition of metal increased the conductivity of the films. Copper, however, showed some anomalous behaviour due to the formation of Cu2O nanocrystals. The effective optical bandgap of the films depended on the metal element, with Mo having the least effect and Au the greatest. Mo tended to form carbides in the film at higher doses, limiting its incorporation as nanoclusters. Structural analysis by the X-ray absorption near edge structure (XANES) techniques using synchrotron radiation showed that the C host matrix was not affected by the nanocomposite formation; however some stress might appear for high doses of Au and Cu. Annealing at 300 degrees Celsius caused graphitisation, increased the conductivity and lowered the stress.
1. dual cathode pulsed cathodic-arc (PCA) from silver and graphite cathodes; and
2. Ag cathodic-arc in reactive methane (CH4) atmosphere.
Moreover, we examined the formation of nanocomposite films which were formed when different metals such as Mo, Au, Ag, or Cu were inserted into a carbon host matrix. A novel 'selective bias' filter-cathodic-arc deposition method that allowed the co-deposition of C and various metal ions without creating heavy-ion damage and re-sputtering was used for this purpose. The addition of metal increased the conductivity of the films. Copper, however, showed some anomalous behaviour due to the formation of Cu2O nanocrystals. The effective optical bandgap of the films depended on the metal element, with Mo having the least effect and Au the greatest. Mo tended to form carbides in the film at higher doses, limiting its incorporation as nanoclusters. Structural analysis by the X-ray absorption near edge structure (XANES) techniques using synchrotron radiation showed that the C host matrix was not affected by the nanocomposite formation; however some stress might appear for high doses of Au and Cu. Annealing at 300 degrees Celsius caused graphitisation, increased the conductivity and lowered the stress.