Zhang Yanni
,
Han Yong
,
Zhang Lan
材料科学技术(英文)
doi:10.1016/j.jmst.2016.06.007
SrTiO3 nanotube films with good adhesion strengths to Ti substrates were fabricated by using a hybrid approach with a modified anodization and a hydrothermal treatment (HT). The effect of Sr2+ concentration in HT solutions on the morphologies and phase components of the nanotubes were investigated, the SrTiO3 nanotubes formation mechanism was explored, and the adhesion strengths, hydrophilicity and apatite-forming ability of the SrTiO3 nanotubes were also evaluated. The results demonstrated that with increasing the incorporation of Sr2+ into the nanotubes, no obvious changes of the lengths and outer diameters of the nanotubes were observed, but the wall thickness and the crystallinity of SrTiO3 in the nanotubes increased. The accumulation of Sr at the inner tube wall indicated that the reaction of Sr2+ with TiO2 mainly occurred in the vicinity of internal surfaces of the closely arranged nanotubes. The formation of the SrTiO3 nanotubes could be attributed to an in situ dissolution-recrystallization process. The SrTiO3 nanotubes exhibited good hydrophilicity and bioactivity, and the induced apatite preferred to nucleate on the nanotubes with higher crystallinity and Sr content, indicating a good bio-adaptability of the SrTiO3 nanotubes for orthopedic application.
关键词:
SrTiO3 nanotubes
,
Modified anodization
,
Hydrothermal treatment
,
Bio-adaptability
Lihong Xue Youwei Yan
材料科学技术(英文)
Highly oriented barium titanate (BaTiO3) thin films on Pt substrate were fabricated by combination of electrophoretic deposition with hydrothermal treatment. The structure and morphology of thin films were characterized by X-ray diffraction and field-emission scanning electron microscopy. It is found that the titania precursor film, Ba(OH)2 oncentration and hydrothermal temperature play crucial roles in the film morphology and orientation. The BaTiO3 thin films with highly (110) preferred orientation can be formed on polycrystalline Pt substrate by appropriate adjustment of the reaction conditions. The orientation parameter f of highly oriented BaTiO3 films was up to 1.00. The films exhibited a smooth and crack-free surface and remained in the layered structure. In situ topotactic transformation and dissolution-crystallization mechanisms were proposed to explain the morphology and orientation of BaTiO3 films during hydrothermal treatment.
关键词:
Barium titanate
,
Preferred orientation
,
Electrophoretic deposition
,
Hydrothermal treatment