The role of graphene oxide interlayer on corrosion barrier and bioactive properties of electrophoretically deposited ZrO2-10 at. % SiO2 composite coating on 316 L stainless steel.

In order to overcome the poor adhesion of zirconia-silica coating electrophoretically deposited on 316 L stainless steel, graphene oxide (GO) was used as an interlayer. The effect of this interlayer on morphological, microstructural, corrosion performance and bioactivity behavior of ZrO2-10 at. % SiO2 coating was studied. The zirconia-silica coating with the GO interlayer revealed a higher barrier performance as a more compact and a greater adhesive layer to the substrate was created. Indeed, the GO interlayer led to an improvement in apatite formation on zirconia-silica coating surface probably due to create higher roughness. Briefly, the GO interlayer was effective on enhancement of electrochemical performance and biological property of zirconia-silica composite coating, making it a suitable candidate for biomaterials applications.

Electrophoretic deposition of chitosan reinforced graphene oxide-hydroxyapatite on the anodized titanium to improve biological and electrochemical characteristics.

Chitosan reinforced hydroxyapatite-graphene oxide (CS-GO-HA) nanocomposite coatings were developed using electrophoretic deposition process in order to improve the biological and electrochemical properties of Ti surface. Moreover, the role of anodized layer on the physical and electrochemical properties of the CS-GO-HA nanocomposite coating was evaluated. After synthesize of HA-GO nanopowder using a sol-gel process, nanocomposite coatings with various concentrations of chitosan (0.5, 1 and 1.5 mg/ml) were produced. Increasing the chitosan content lowered the deposition rate of HA-GO nanoparticles, reduced the coating thickness and diminished apatite-formation ability and biocompatibility. Noticeably, MG63 cell viability significantly reduced form 119.3 ±â€¯5.1 (% control) to 51.9 ±â€¯14.8 (% control), when the chitosan concentration increased from 0.5 to 1.5 mg/ml. In addition, the CS-GO-HA coating containing 0.5 mg/ml chitosan revealed the best barrier property owing to the less crack formation. Furthermore, anodizing of titanium substrate and formation of TiO2 nanotube (TiNT) resulted in the formation of crack-free and homogeneous CS-GO-HA coatings without any observable defect. Moreover, the TiNT formation noticeably improved barrier resistance of the coating (6.7 times) due to better adhesion governed between coating and substrate. Our results confirmed that the surface modification using both anodizing of Ti substrate and electrophoretic deposition of ternary CS-GO-HA nanocomposite coating with 0.5 mg/ml chitosan successfully improves electrochemical properties, bioactivity and cell function, which makes it promising for bone implant applications.