Synthesis, characterization, and interfacial adhesion of titania iodine‐doped nanotubes architectures on additively manufactured Ti‐6Al‐4V implant

Abstract

This study aimed to synthesize, characterize, and evaluate the adhesionstrength of titania nanotubes (titania nanotubes) and iodine-doped titaniananotubes (I-titania nanotubes) architectures on the additively manufacturedTi-6Al-4 V (Ti64) implant surface. The titania nanotubes and I-titania nano-tubes were synthesized through two stages of electrochemical anodization,whereby titania nanotubes are anodically fabricated through a conventionalapproach and then modified by replacing the ethylene glycol electrolyte withpotassium iodide solution. The characterization results revealed the formationof α-Ti, β-Ti, and titanium iodide (TiI2) phases on the titania nanotubes and I-titania nanotubes surfaces. The morphology of titania nanotubes exhibits aconsistent diameter, evenly distributed, well-ordered array, and denselypacked nanotubular structures. Formation of a water-soluble fluoride-rich[TiF6]2 complexes in the inner titania nanotubes surface and incessant nano-tube’s sidewall etching resulted in poor interfacial titania nanotubes adhesionto the titanium-substrate surface. Iodine doping on the titania nanotubes isbelieved to reduce the [TiF6]2 complexes accumulation and the titania nano-tubes sidewall etching. This facilitates the adhesion and interfacial mechan-ical anchorage between the titania nanotubes and the surface of the Ti64 im-plant. The hardness and adhesion strength of the titania nanotubes increasedby more than 50 %, due to the formation of a hard titanium iodide film at thetitania nanotubes/I-titania nanotubes surfaces and interfaces.