Characterization of Zn/Mg-enriched calcium phosphate coating produced by the two-step pulsed electrodeposition method on titanium substrate

Abstract

Zn/Mg-enriched calcium phosphate were coated on a titanium surface with a nanotube structure by the two-step pulsed electrodeposition method. In order to create a nanotube structure on the substrate, titanium samples were anodized at different voltages and times, and then were alkalinized for 10 min. An electrolyte solution containing calcium chloride and sodium phosphate was used for the two-step pulsed electrodeposition method. Magnesium chloride and zinc chloride were added to the electrolyte solution by adding Zn/Mg elements to the coating. The coating process was carried out different ratios of deposition to relaxation time. In order to investigate the morphology of phases, grain size and coating properties, the samples were subjected to various tests including XRD, FTIR, FE-SEM, EDX, antibacterial and protein uptake. The coating was included of the brushite cement (Dicalcium Phosphate Dehydrate (DCPD, CaHPO42H2O)) and the β-tricalcium phosphate (β -TCP (Ca3 (PO4)2)) precipitates. The results showed that, the coating morphology is affected by the coating conditions and the concentration of Zn and Mg element. The results of protein uptake and antibacterial tests revealed that the maximum amount of protein uptake and antibacterial activity are obtained for 30Mg-DCPD sample(with 3 × 10−3 mole of magnesium ion) and 20Zn-DCPD sample(with 2 × 10−3 mole of zinc ion) respectively.