Sol-gel derived AgMgO films for antibacterial and bioactive surface modification of niobium metal

Silver-containing MgO (AgMgO) films with the Ag/Mg molar ratio of 0, 0.3%, 1%, 3% and 6%, respectively were sol-gel coated on niobium metal to improve its antibacterial property and bioactivity, and niobium had been alkali pretreated to increase the film thickness. Sodium niobate nanofibers or nanobelts are formed at the surface of alkali treated niobium. For the coated samples, thick and rough Nb2O5 layers are grown due to oxidation of niobium at 400 °C, and silver exists mainly as silver niobate in the AgMgO films. In the potentiodynamic polarization test, the coated samples exhibit better corrosion resistance than the polished sample. The simulated body fluid test demonstrates bioactivity of the coated sample with 3% Ag. Antibacterial activity of the coated samples against Escherichia coli is silver-content dependent, obtaining antibacterial ratios of 100% at the Ag content ≥1%. The present work would provide a facile method for antibacterial and bioactive surface modification of niobium metal in osteo-implant applications. [Display omitted] •AgMgO films were sol-gel coated on alkali pretreated niobium substrate.•Silver exists mainly as silver niobate in the AgMgO films.•The coated samples have better corrosion resistance and exhibit bioactivity.•The coated samples demonstrate good antibacterial activity against E. coli.