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

Bioactive sodium-substituted titania coating on 316L SS substrate was prepared. XRD patterns exhibited the formation of a mixture of two phases (Na₂Ti₃O₇, Na₂Ti₆O₁₃) with monoclinic structure. FTIR spectra showed that the set of overlapping peaks in the range of 800–400 cm⁻¹ 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.