title: Thermally oxidized titania nanotubes enhance the corrosion resistance of Ti6Al4V.
abstract: The negative impact of in vivo corrosion of metallic biomedical implants remains a complex problem in the medical field. We aimed to determine the effects of electrochemical anodization (60V, 2h) and thermal oxidation (600°C) on the corrosive behavior of Ti-6Al-4V, with serum proteins, at physiological temperature. Anodization produced a mixture of anatase and amorphous TiO2 nanopores and nanotubes, while the annealing process yielded an anatase/rutile mixture of TiO2 nanopores and nanotubes. The surface area was analyzed by the Brunauer-Emmett-Teller method and was estimated to be 3 orders of magnitude higher than that of polished control samples. Corrosion resistance was evaluated on the parameters of open circuit potential, corrosion potential, corrosion current density, passivation current density, polarization resistance and equivalent circuit modeling. Samples both anodized and thermally oxidized exhibited shifts of open circuit potential and corrosion potential in the noble direction, indicating a more stable nanoporous/nanotube layer, as well as lower corrosion current densities and passivation current densities than the smooth control. They also showed increased polarization resistance and diffusion limited charge transfer within the bulk oxide layer. The treatment groups studied can be ordered from greatest corrosion resistance to least as Anodized+Thermally Oxidized > Anodized > Smooth > Thermally Oxidized for the conditions investigated. This study concludes that anodized surface has a potential to prevent long term implant failure due to corrosion in a complex in-vivo environment.
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 851 S. Morgan St, Chicago, IL, 60607, USA; Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA.
authors.forename: John
authors.initials: J
authors.lastname: Grotberg
authors.affiliation: Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA; Mechanical Engineering-Engineering Mechanics, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA.
authors.forename: Azhang
authors.initials: A
authors.lastname: Hamlekhan
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 851 S. Morgan St, Chicago, IL, 60607, USA; Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA.
authors.forename: Arman
authors.initials: A
authors.lastname: Butt
authors.affiliation: Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA; Mechanical Engineering-Engineering Mechanics, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA.
authors.forename: Sweetu
authors.initials: S
authors.lastname: Patel
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 851 S. Morgan St, Chicago, IL, 60607, USA; Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Royhman
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 851 S. Morgan St, Chicago, IL, 60607, USA; Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA; Mechanical Engineering-Engineering Mechanics, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA.
authors.forename: Tolou
authors.initials: T
authors.lastname: Shokuhfar
authors.affiliation: Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA; Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 S. Paulina, Chicago, IL, 60612, USA.
authors.forename: Cortino
authors.initials: C
authors.lastname: Sukotjo
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 851 S. Morgan St, Chicago, IL, 60607, USA; Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA.
authors.forename: Christos
authors.initials: C
authors.lastname: Takoudis
authors.affiliation: Institute of Biomaterials, Tribocorrosion and Nanomedicine (IBTN), 851 S. Morgan St, Chicago, IL, 60607, USA; Department of Orthopedics, Rush University Medical Center, 1611 W. Harrison, Chicago, IL, 60612, USA. Electronic address: mathew_t_mathew@rush.edu.
authors.forename: Mathew T
authors.initials: MT
authors.lastname: Mathew
mesh_terms: D000497:Alloys; D003343:Corrosion; D006358:Hot Temperature; D043942:Nanotubes / Q000737:chemistry*; D011475:Prosthesis Failure; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; C031462:titanium alloy (TiAl6V4); C009495:titanium dioxide; D014025:Titanium
keywords: Anatase; Corrosion; Nanopore; Nanotube; Rutile; Titanium; Wettability