title: A Novel Investigation of the Formation of Titanium Oxide Nanotubes on Thermally Formed Oxide of Ti-6Al-4V.
abstract: Traditionally, titanium oxide (TiO2) nanotubes (TNTs) are anodized on Ti-6Al-4V alloy (Ti-V) surfaces with native TiO2 (amorphous TiO2); subsequent heat treatment of anodized surfaces has been observed to enhance cellular response. As-is bulk Ti-V, however, is often subjected to heat treatment, such as thermal oxidation (TO), to improve its mechanical properties. Thermal oxidation treatment of Ti-V at temperatures greater than 200°C and 400°C initiates the formation of anatase and rutile TiO2, respectively, which can affect TNT formation. This study aims at understanding the TNT formation mechanism on Ti-V surfaces with TO-formed TiO2 compared with that on as-is Ti-V surfaces with native oxide. Thermal oxidation-formed TiO2 can affect TNT formation and surface wettability because TO-formed TiO2 is expected to be part of the TNT structure. Surface characterization was carried out with field emission scanning electron microscopy, energy dispersive x-ray spectroscopy, water contact angle measurements, and white light interferometry. The TNTs were formed on control and 300°C and 600°C TO-treated Ti-V samples, and significant differences in TNT lengths and surface morphology were observed. No difference in elemental composition was found. Thermal oxidation and TO/anodization treatments produced hydrophilic surfaces, while hydrophobic behavior was observed over time (aging) for all samples. Reduced hydrophobic behavior was observed for TO/anodized samples when compared with control, control/anodized, and TO-treated samples. A method for improved surface wettability and TNT morphology is therefore discussed for possible applications in effective osseointegration of dental and orthopedic implants.
authors.affiliation: 1  Department of Bioengineering, University of Illinois at Chicago, Chicago, Ill.|2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.
authors.forename: Arman
authors.initials: A
authors.lastname: Butt
authors.affiliation: 2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.|3  Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, Mich.
authors.forename: Azhang
authors.initials: A
authors.lastname: Hamlekhan
authors.affiliation: 1  Department of Bioengineering, University of Illinois at Chicago, Chicago, Ill.|2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.
authors.forename: Sweetu
authors.initials: S
authors.lastname: Patel
authors.affiliation: 2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.|4  Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, Ill.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Royhman
authors.affiliation: 2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.|4  Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, Ill.
authors.forename: Cortino
authors.initials: C
authors.lastname: Sukotjo
authors.affiliation: 2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.|5  Department of Orthopedics, Rush University Medical Center, Chicago, Ill.
authors.forename: Mathew T
authors.initials: MT
authors.lastname: Mathew
authors.affiliation: 2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.|3  Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, Mich.
authors.forename: Tolou
authors.initials: T
authors.lastname: Shokuhfar
authors.affiliation: 1  Department of Bioengineering, University of Illinois at Chicago, Chicago, Ill.|2  Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), Chicago, Ill.|6  Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Ill.
authors.forename: Christos
authors.initials: C
authors.lastname: Takoudis
mesh_terms: D008855:Microscopy, Electron, Scanning; D043942:Nanotubes; D016348:Osseointegration; D010087:Oxides; D013499:Surface Properties; D014025:Titanium
chemical_list: D010087:Oxides; C009495:titanium dioxide; D014025:Titanium
keywords: Ti-6Al-4V alloy; anatase-rutile; anodization; nanotubes; osseointegration; thermal oxidation