Electrophoretic deposition, microstructure and properties of multicomponent sodium alginate-based coatings incorporated with graphite oxide and hydroxyapatite on titanium biomaterial substrates

Abstract Multicomponent sodium alginate-based coatings reinforced with hydroxyapatite (HA) nanoparticles and graphite oxide (GtO) nanosheets consisting of graphene oxide (GO) packages were electrophoretically deposited on CP-Ti and Ti-13Nb-13Zr alloy. The suspension properties, electrophoretic deposition (EPD) mechanisms and kinetics were studied to deposit dense coatings. The coatings consisting of a sodium alginate matrix revealed a homogeneous distribution of HA nanoparticle agglomerates and GtO flakes oriented parallel to the surface of the coating. The coating topography depended significantly on the surface roughness of the substrates. GtO flakes enhanced the adhesion of coatings to the substrates. All multicomponent coatings had a hydrophilic surface, but the hydrophilicity was higher for coatings deposited on the polished alloy substrate than for coatings obtained on the acid etched CP-Ti. The surface free energy of the coated CP-Ti substrates was about 30% higher than the one of uncoated titanium. For the coatings deposited on the alloy the surface free energy was about 65% higher than that of the alloy. The GtO/HA/sodium alginate coatings increased the corrosion resistance of titanium alloy. Considering their microstructure and properties, the newly-developed multicomponent coatings are interesting for further development of biologically enhanced titanium surfaces.