Synthesis and characterization of nanoporous sodium-substituted hydrophilic titania ceramics coated on 316L SS for biomedical applications

Abstract

Bioactive sodium-substituted titania coating on 316L SS substrate was prepared. XRD patterns exhibited the formation of a mixture of two phases (Na 2 Ti 3 O 7 , Na 2 Ti 6 O 13 ) with monoclinic structure. FTIR spectra showed that the set of overlapping peaks in the range of 800-400 cm À1 are related to Ti-O and Ti-O-Ti groups. SEM-EDAX, AFM, and TEM showed the surface morphology of the coated surface to be nanoporous and uniform. The influence of the bioactivity of the coating in a simulated body fluid (SBF) medium was examined. Excellent adhesion of the ceramic composites to the substrate was achieved. The hydrophilic nature of the sodium titanate coating induced the formation of hydroxyapatite layer on the metal surface. The corrosion protection performance of the coatings has been evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy measurements, which proved increased corrosion resistance of nanosodium titanate-coated 316L SS. These results imply that the sodium titanate-coated 316L SS acts as a barrier layer to the metallic substrate.

Corrosion behaviour of biomedical β-titanium alloys with the surface-modified by chemical etching and electrochemical methods

“…The Ceff calculated from the values listed in Table 1 for the diverse immersion periods ranged from 18 to 9 μF.cm −2 for the porous layer and 12 to 3 μF.cm −2 for the compact inner layer, values similar to the ones observed for AISI 316L stainless steel immersed in physiological solutions [40,41]. This capacitance reduction is related to a passive layer thickness increase [18,42].…”

Developing alkaline titanate surfaces for medical applications

“…A different approach is to use a sol–gel methodology generating sodium titanate structures on 316L SS (Devi et al . [324]). This also demonstrated a nanoporous topography, albeit with a different morphology and no chemical bond to the metal surface.…”

Surface Modifications for Implants Lifetime extension: An Overview of Sol-Gel Coatings

“…However, entirely inorganic sol-gel coatings are also proposed as protective layers enhancing both cytocompatibility and corrosion resistance of the coated implants. In particular, sol-gel ZrO 2 [130], ZrO 2 SiO 2 [131], Nb 2 O 5 [132] SrO-SiO 2 -TiO 2 [133], or TiO 2 -based coatings [134][135][136][137][138][139][140] have been proposed to improve the corrosion resistance of several metal substrates, such as steels [130,137,140], titanium grade 4 [131], Ti6Al4V [134,138], NiTi alloy [133,139], and Mg-based alloy [135,136]. Liu et al [67], Cheng et al [141], and Chiu et al [142] demonstrated that the presence of the sol-gel coatings improves NiTi alloy corrosion resistance reducing Ni release, which can cause allergenic and toxic effects when its concentration exceeds a certain level in the body.…”