Synthesis of hydroxyapatite from eggshell and its electrochemical characterization as a coating on titanium

This work reports the surface modification of titanium through the deposition of a hydroxyapatite coating synthesized from natural sources. Hydroxyapatite was synthesized from eggshell using a wet precipitation method. It was deposited as a coating on a Ti surface using electrophoretic deposition (EPD) at different electrophoretic deposition times and voltages. The electrochemical evaluation of the obtained coatings was performed through potentiodynamic polarization curves in a simulated physiological solution. The results showed that the eggshell is an excellent alternative for the synthesis of hydroxyapatite, and that its heat treatment at 700 °C shows the best crystallinity conditions. The optimum conditions for deposition of the hydroxyapatite coatings were 30 V and 18 min. Potentiodynamic polarization tests showed that hydroxyapatite coatings improve the chemical stability of the Ti surface when subjected to the corrosive action of simulated physiological solutions at 37 °C.