Adsorption of Ba²⁺ ions at the hydroxyapatite/NaCl solution interface

The study of the kinetics of barium adsorption at the hydroxyapatite/electrolyte interface using the radioactive isotope ¹³³Ba²⁺ was carried out. The course of adsorption kinetics indicates that at the beginning adsorption proceeds quickly and then slowly. Such adsorption kinetics is best described by the multiexpotential equation. The adsorption of Ba²⁺ ions at the hydroxyapatite/ electrolyte interface proceeds via their adsorption of ions on the surface groups with the release of proton and the exchange of Ca ions from the crystal lattice. The adsorption process has an insignificant effect on the crystal lattice parameters and crystallinity degree but due to the decrease of zeta potential leads to particles aggregation.