Effect of Na+ and NaOH concentrations on the surface morphology and dissolution behavior of hydroxyapatite

Hydroxyapatite coatings were fabricated by the electrochemical deposition method on carbon/carbon composites and were post-treated with different concentrations and pH values of boiling NaOH solution. This study aimed to investigate the effect of Na+ and NaOH concentrations on the structure, surface morphologies, and dissolution of hydroxyapatite coatings. The coating structure and its surface morphologies were determined by x-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The concentration of Ca2+ was measured by an inductively coupled plasma optical emission spectrometer. Results revealed that significant differences can be seen between the two hydroxyapatite coatings in the morphology and components. in the morphology and components between the two hydroxyapatite coatings. The influence of NaOH concentration on Ca2+ dissolution concentration was larger than that of the Na+ concentration.