Development of Alkoxide Precursors-Based Hybrid Coatings on Ti-6Al-4V Alloy for Biomedical Applications: Influence of pH of Sol

Bioactivity of Ti6Al4V alloy with bioglass and corrosion protection by silane coating

“…Microcavities and microcracks can be observed on the surface of the as-received Ti6Al4V substrate [Figure 2 The MAP/TEOS films deposited on the metallic substrates seemed thin since the surface irregularities (grinding grooves) of the metallic substrates were still visible from the observation of Figure 2(c,d). Moreover, light and dark regions can be observed, which can be attributed to the variation in film thickness (Salvador et al, 2018). The dark regions corresponded to the microcavities and grooves regions observed on the surface of the metallic substrate, where there was probably more film accumulation (Zhao et al, 2017).…”

“…Following the cleaning stage, the substrates were submitted to alkaline treatment in a sodium hydroxide solution (NaOH) (Neon) 0.01 mol.L -1 (pH = 11.5) for 3 min at 24 °C and dried in cold air. This process activates the substrate surface for better film adhesion (Salvador et al, 2018).…”

“…Initially, the sol was prepared at 24 °C under magnetic agitation. Next, the distilled water was acidified with acetic acid to adjust the pH content to 4.0 (Kunst et al, 2015;Salvador et al, 2018;van Ooij et al, 2005).…”

“…The morphology of the uncoated and coated surfaces was evaluated using a Field Emission Gun Scanning Electronic Microscopy (FEGSEM) equipment (Tescan, model Mira3, Czech Republic) and an Energy Dispersion X-Ray Spectroscopy (EDS) detector (Oxford, model X-Max50, Czech Republic) coupled to the FEGSEM equipment. The adhesion of the films to the substrates and the adhesion rate (percent of film area removed) were evaluated by the tape test following the ASTM D3359-09 standard (Salvador et al, 2018), with the aid of the FEGSEM technique.…”

“…A conventional three-electrode cell was used to monitor the evolution of the OCP values as a function of time, which consisted of the sample (working electrode), the saturated calomel reference electrode (SCE), and the platinum counter electrode. The measurements were carried out in the absence of agitation at 24 °C with SBF as the electrolyte (Salvador et al, 2018). The evolution of OCP values was monitored during the first hour of immersion.…”