Fabrication And Properties Of Composite Oxide Nanostructures

Due to their novel properties titania nanomaterials have been widely used in photocatalitic, photoelectronic conversion and sensor fields. Through anodization a layer of TiOx-based composite nanostructures could grow on the surface of Ti and Ti alloys. In this work, the effect of anodization voltage and alloying elements on the morphology and composition of the composite nanostructures was investigated systematically. Thermal stability of the composite nanostructures and in vitro bioactivity of Ti-Al-V-O nanostructures were also investigated.With increase of the anodization voltage, the diameter and the length of nanotubes become bigger and longer, respectively. Alloying elements promote the formation of composite nanotubes at low anodization voltage. For the anodization of Ti6Al4V alloy, it was found that Al element could keep the formation of nanotubes and V element could not keep the formation of nanotubes due to its high dissolution rate. Investigation on the anodization of Ti35NbxZr alloys revealed that, with increaset of the Zr content in the original Ti35NbxZr alloys, the diameter and length of the as-grown Ti-Nb-Zr-O nanotubes became smaller and longer, respectively. A comparison of all the composite nanostructures fabricated from Ti and its alloy indicate that Ti-O nanotubes fabricated from Ti could withstand a temperature of 650 o C. Ti-Al-V-O nanotubes could withstand 675oC, while Ti-Al-V-O nanopores could withstand a lower temperature than that of Ti-Al-V-O nanotubes. Ti-Nb-Zr-O nanotubes presented the best thermal stability as they could withstand 750oC without a damage of their tube-like nanostructures. We also found that the Ti-Al-V-O nanostructures possess a good in vitro bioactivity.