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 adhesion strength of titania nanotubes (titania nanotubes) and iodine‐doped titania nanotubes (I‐titania nanotubes) architectures on the additively manufactured Ti‐6Al‐4 V (Ti64) implant surface. The titania nanotubes and I‐titania nanotubes were synthesized through two stages of electrochemical anodization, whereby titania nanotubes are anodically fabricated through a conventional approach and then modified by replacing the ethylene glycol electrolyte with potassium iodide solution. The characterization results revealed the formation of α‐Ti, β‐Ti, and titanium iodide (TiI 2 ) phases on the titania nanotubes and I‐titania nanotubes surfaces. The morphology of titania nanotubes exhibits a consistent diameter, evenly distributed, well‐ordered array, and densely packed nanotubular structures. Formation of a water‐soluble fluoride‐rich [TiF 6 ] 2 complexes in the inner titania nanotubes surface and incessant nanotube′s sidewall etching resulted in poor interfacial titania nanotubes adhesion to the titanium‐substrate surface. Iodine doping on the titania nanotubes is believed to reduce the [TiF 6 ] 2 complexes accumulation and the titania nanotubes sidewall etching. This facilitates the adhesion and interfacial mechanical anchorage between the titania nanotubes and the surface of the Ti64 implant. The hardness and adhesion strength of the titania nanotubes increased by more than 50 %, due to the formation of a hard titanium iodide film at the titania nanotubes/I‐titania nanotubes surfaces and interfaces.