Nanotube Morphology Changes of Ti–xTa–Ag–Pt Alloys with Ta Content for Biomaterials

In this study, nanotube morphology changes of Ti–xTa–Ag–Pt alloys with Ta content for biomaterials were researched using various experimental instruments. Ti–xTa–Ag–Pt alloys were manufactured in an Ar atmosphere using a vacuum arc-melting furnace with Ta contents of 10 and 50, and then heat-treated at 1100 °C for 1 hr. Nanotube formation of Ti–xTa–Ag–Pt (x = 10, 50 wt%) alloys were performed using a DC power of 30 V in 1.0 M H3PO4 + 0.8 wt% NaF electrolyte solution. Surface characteristics were investigated using an optical microscope, X-ray diffractometer, field-emission scanning electron microscope, energy-dispersive X-ray spectroscopy, and Image analyzer (Image J). Ti–10Ta–Ag–Pt alloy had a needle-like structures, and Ti–Ti–50Ta–Ag–Pt showed the mixed structure (equiaxed and needle-like structures). As the Ta content increased, the α-phase decreased and the β-phase increased. The highly ordered nanotubes were formed on the β-phase, whereas disordered nanotubes were formed on needle-like structure of α-phase in Ti–10Ta–Ag–Pt alloy. As the Ta content increases, large and small nanotube diameters became smaller in size. Anatase and rutile phases were formed on the alloy surface. Ta, Ag, and Pt elements were uniformly distributed over the entire surface and at the edge or inside of the nanotube.

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

Alkane dehydrogenation over heterogeneous catalysts has attracted renewed attention in recent years. Here, well-defined catalysts based on isolated metal sites and supported Pt-alloys prepared via SOMC are discussed and compared to classical systems.