Synthesis And Properties Of Titanate/TiO₂Composite Nanotube Arrays

Titanate/TiO₂composite nanotube arrays have important applications inphotoelectrochemical water splitting, photocatalytic degradation of environmentalorganic pollutants and biological coating due to their novel and unique physical,chemical and biological properties. In this thesis, the synthesis and formationmechanism of titanate/TiO₂composite nanotube arrays on Ti are systematicallyinvestigated, the biological properties of SrTiO3/TiO₂and ZnTiO3/TiO₂compositenanotube coating also be studied. The main results are summarized as follows:（1） TiO₂nanoparticles/nanotube arrays （NPs/NTAs） and TiO₂nanorod composite ofTiO₂nanoparticles are produced from as-anodized amorphous TiO₂nanotube arraysby hydrothermal treatment in water, and their synthesis mechanism, photocatalyticactivity and photoelectrochemical properties were researched. This synthesismechanism provides the foundation of theory of synthesis titanate/TiO₂compositenanotube structure.（2） SrTiO3, BaTiO3, CaTiO3/TiO₂composite nanotube structure were prepared byhydrothermal treatment the amorphous of TiO₂nanotubes in Sr（OH）₂，Ba（OH）2，Ca（OH）2alkaline solution. ZnTiO3，NiTiO3，CoTiO₃/TiO₂composite nanotubestructure were fabricated in MAc2（M=Zn，Ni，Co） non-alkaline solution，and theircorresponding growth models were proposed.（3） SrTiO3/TiO₂nanotubes （NT-Sr） with different tube diameters and Sr releaserates have been fabricated by hydrothermal treatment of titania nanotubes formed at10and40V in Sr（OH）₂solution. Long-lasting and controllable Sr release is observedfrom the NT-Sr samples with no cytotoxicity. In particular, sample NT10-Sr3formed by hydrothermal treatment of titania nanotube anodized at10V in Sr（OH）₂solution at200℃for3h shows the best effects in inducing MSC osteogenicdifferentiation due to the proper Sr release amount and suitable multiple nanoscalestructure with even protein adsorption favoring cell functions. The NT-Sr gives riseto good osteogenic activity without the need to apply foreign complex biomolecules.The materials are easy to fabricate and have good stability that facilitating large-scaleindustrial production, storage, transport, sterilization and clinical use.（4） ZnTiO3/TiO₂composite nanotube structures with different Zn content werepreparation by hydrothermal treatment of the as-anodized amorphous TiO₂nanotubein Zn（AC）₂solution for different time. The results show that NT-Zn₃preparation bythe amorphous TiO₂nanotube hydrothermal treatment at200℃for3h in0.1M Zn（AC）₂solution, have the best antibacterial properties，noncytotoxicity to osteoblast,and no effect of osteoblast proliferation, as well as promort alkaline phosphatase（ALP） gene expression and osteogenesis. NT-Zn₃has potential application in medicaltitanium implants materials.