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The success of an orthopedic implant therapy depends on successful bone integration and the prevention of microbial infections. In this work, plasma electrolytic oxidation (PEO) was performed to deposit TiO 2 coatings enriched with Ca, P and Ag on titanium to improve its surface properties and antibacterial efficacy while maintaining normal biological functions and thus to enhance the performance of orthopedic implants. After PEO treatment, the surface of Ti was converted to anatase and rutile TiO 2 , hydroxyapatite and calcium titanate phases. The presence of these crystalline phases was further increased with an increased Ag content in the coatings. The developed coatings also exhibited a more porous morphology with an improved surface wettability, roughness, microhardness and frictional coefficient. In vitro antibacterial assays indicated that the Ag doped coatings can significantly prevent the growth of both Staphylococcus aureus and Escherichia coli by releasing Ag + ions and the ability to prevent these bacteria was enhanced by increasing the Ag content in the coatings resulting in a maximal 6-log reduction of E. coli and a maximal 5-log reduction of S. aureus after 24 hours of incubation. Moreover, the in vitro cytocompatibility evaluation of the coatings exhibited that the osteoblast (MC3T3) cell integration on the PEO-based coatings were greatly improved compared to untreated Ti and no notable impact on their cytocompatibility was observed on increasing the amount of Ag in the coating. In conclusion, the coating with favorable physico-chemical and mechanical properties along with controlled silver ion release can offer an excellent antibacterial performance and osteocompatibility and can thus become a prospective coating strategy to face current challenges in orthopedics.

In this study, Ni or Co + Ni bonded NbC matrix cermets with secondary carbides (Mo2C and WC) as well as Ti(C0.5N0.5) were prepared by liquid phase sintering at 1450°C in vacuum. Detailed microstructural investigation was performed by SEM, EPMA and XRD analysis. The microstructure, mechanical properties as well as the C45 (HB140) steel turning performance of the cermets were investigated, and compared with a commercial Ti(C0.5N0.5) based cutting insert. The sintering results indicated that the partial substitution of NbC by Ti(C0.5N0.5) had a significant effect on the core-rim microstructure and refinement of NbC solution grains, as well as improved mechanical properties of the NbC-Ti(C0.5N0.5) cermets. The phase constitution and composition of the cermets were supported by thermodynamic equilibrium calculations. All sintered cermets were composed of a fcc solid solution metal binder and a cubic core-rim (Nb,Ti,Mo,W)(C,N) solution phase, as well as an independent Nrich Ti(C,N) phase. The NbC-Ti(C0.5N0.5) and Ti(C0.5N0.5) matrix cermets had a comparable HV30 of 1500-1600 kg/mm 2 and a similar fracture toughness of 8.0 MPa m 1/2 .

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The effect of electrochemical reduction of carbon dioxide (CO 2 ) by changing the structure and morphology of FeTiO 3 nanoparticle prepared through sol-gel and hydrothermal methods is explained in this study. FeTiO 3 nanoparticles were used as a cathode where as a stainless steel plate and CO 2 − saturated NaHCO 3 were used as an anode and an electrolyte, respectively. The cyclic voltammetry and linear sweep voltammetry analysis were carried out comprehensively on FeTiO 3 -SG-and FeTiO 3 -HT-coated electrodes to decouple the electrochemical reduction processes of CO 2 in aqueous solution. The charge transfer resistance and the product gases were studied using electrochemical impedance spectroscopy and gas chromatography, respectively. The observed results were analyzed in light of structure/morphology, particle size, and surface area of FeTiO 3 nanoparticles and their influence on the effective cathodic behavior in CO 2 to CO reduction.