Ag-TiO 2 films (Ag/Ti53?3, 9?1 at-%) were sol-gel coated on Ti-6Al-4V alloy that had been surface roughened by the NaOH-HCl treatment for antibacterial applications. Scanning electron microscopy observation showed that pore size of the surface layer of NaOH-HCl treated Ti6Al-4V alloy increased with the NaOH concentration. Ag-TiO 2 films on the surface roughened substrate were adherent and crack-free. X-ray photoelectron spectroscopy and Auger electron spectroscopy analyses indicated that Ag existed in metallic state, and the films completely covered the roughened substrate. X-ray diffraction peaks of the substrate and anatase TiO 2 were detected. The Ag-TiO 2 films on the roughened substrate exhibited good adhesion quality and high cohesion strength in the indentation test. The potentiodynamic polarisation test showed that the TiO 2 and Ag-TiO 2 films improved corrosion resistance of the substrate.

Ranking intuitionistic fuzzy values (IFVs) and interval-valued intuitionistic fuzzy values (IVIFVs) is an important and necessary work in intuitionistic fuzzy group decision making. Since the set of all IFVs is a poset and inclusion measure indicates the degree to which a given element of a poset is contained in another one. This paper studies hybrid monotonic (HM) inclusion measures of IFVs and IVIFVs respectively and discuss their applications to group decision making. Firstly, HM inclusion measure is defined on the posets of all IFVs and IVIFVs respectively. Then HM inclusion measures are studied by constructive approach. Furthermore, the HM inclusion measures are employed to make intuitionistic and interval-valued intuitionistic fuzzy group decisions. Lastly, practical examples are provided to illustrate the developed approaches respectively.

No abstract

MgO and silver-containing MgO (AgMgO, 3.3, 9.1 at% Ag) films were sol-gel coated on titanium to improve its antibacterial property. Thermal analyses of MgAc2·4H2O powder revealed that MgO was crystallized at 400 °C. X-ray diffraction analysis showed that MgO was converted to Mg(OH)2 or Mg5(CO3)4(OH)2·4H2O during the ageing in air. Silver nanoparticles at the surface of AgMgO films were identified by scanning electron microscopy and x-ray photoelectron spectroscopy. The MgO film was about 1.5 um thick. The potentiodynamic polarization test in the Ca-free Hank’s balanced salt solution showed that the coated titanium samples had better corrosion resistance than the polished one. The dissolution of silver nanoparticles resulted in a current peak in the polarization plots. In the antibacterial test against E. Coli, the inhibition zone width was 0.3, 1.6, 2.0 mm for the films with 0, 3.3, 9.1 at% Ag, respectively. The bactericidal mechanisms of the MgO and AgMgO films were discussed. The present work would provide a facile method for antibacterial surface modification of titanium based osteo-implants.

No abstract