Titanium anodization as a surface modification technique using different combinations of aqueous or organic electrolytes, of acidic and alkaline nature

Abstract This study investigates the effect of distinct electrolyte compositions on the morphology, composition and wettability of films produced by anodic titanium oxidation, aiming to obtain surfaces with potential for biomedical applications. The electrolyte set considered herein encompasses diverse key components that provide distinct chemical environments, as one set of solutions is predominantly organic while the other is aqueous in nature. For such a purpose, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS) and field emission scanning electron microscopy (FESEM) analyses were carried out, in addition to measurements of roughness and water contact angle with the modified surfaces. Furthermore, the electrochemical impedance spectroscopy (EIS) was performed aiming to characterize the morphology and structure of modified surfaces, as well as their hydrophilic properties, in addition to establishing a correlation among different current–time profiles during anodization, used electrolytes, and the morphology of films. Experimental conditions leading to nanotube formation were also investigated in galvanostatic mode, and their results were compared to those found by potentiostatic anodization. Results showed that distinct nanotube arrangements significantly affected the surface energy, leading to superhydrophilic properties. Such high wettability is a key factor for enhancing the biological performance of implants, as it is well-documented to facilitate protein adsorption and early osseointegration.