Dependence of Nanotextured Titanium Orthopedic Surfaces on Electrolyte Condition

Abstract

Electrochemical etching of titanium alloy in a fluoride-containing electrolyte results in ordered nanotextured surfaces. The reproducibility of nanotextured surfaces depends on several process parameters, most notably the fluoride ion concentration in the electrolyte. In the present work, electrochemical etching of Ti6Al4V alloy foils in ethylene glycol containing 0.66 wt% NH 4 F and 2% deionized water was carried out at 60 V for 45 minutes. This paper describes the depletion of fluoride ion concentration and contamination of electrolyte upon reuse. Inductively coupled plasma-optical emission spectroscopy was used to measure the dissolution of metal oxides in the electrolyte during etching. We found increasing concentration of the alloy elements Ti, Al, V contaminated the electrolyte due to repeated reuse of the electrolyte. The results show an appreciable log-linear depletion of fluoride ion concentration resulting in a changed surface morphology, chemical composition and etched volume. This paper provides an important insight to changes in surface morphology and surface chemistry with extended reuse of the etching electrolyte, useful for regulatory approvals.

Titanium for Orthopedic Applications: An Overview of Surface Modification to Improve Biocompatibility and Prevent Bacterial Biofilm Formation

“…The material in question demonstrated antibacterial and bioactive properties ( Ferraris et al., 2014 ). Although this method is commonly explored in the literature, a major problem with this method is its tendency to deposit residual ions upon the titanium surface, which have the potential to leech into the adjacent tissue ( Bhosle et al., 2016 ).…”

Structural, Morphological, Topographical Characterization of Titanium Dioxide Nanotubes Metal Substrates for Solar Cell Application

“…also evident from the surface SEM micrograph in Figure 2(a) is the presence of a nanoporous oxide layer covering some of the nanotube, according to theory, the nanotubular growth results from chemical etching in the presence of F _ ions Eq. (3) of the tube walls from both sides leading to formation of nanotube layers [42][43][44][45]. However the oxide layer on top of the nanotubes might be due to the first oxide layer formed from Eq.…”

Nanotextured Titanium Surfaces for Implants: Manufacturing and Packaging Aspects

“…Ethylene glycol (EG) and DI water-based electrolytes containing NH4F are well established recipes for fabricating nanotube morphologies on titanium substrates [31][32][33][34].…”

“…favourable for osteoblast function and to keep fluorine content in the electrolyte as low as possible knowing that anodic nanotubular structures possess residual fluorine from electrolyte species[32,36]. A hybrid electrolyte, using a combination of NH4F and AgF (US patent 9376759)[37] yielding a specific concentration of fluorine and Ag, was used to prepare three different concentrations of silver in the electrolyte while maintaining a constant total fluoride concentration that ensures a consistent nanotube surface.…”