Probing the interaction of (001) carbonated hydroxylapatite surfaces with water: A density functional investigation

Carbonated hydroxylapatite represents one of the most important phases in bone tissues. This discovery led to many successful efforts to characterise its structure and properties at physico-chemical level, with the aim to employ this material in biomedical applications. It is possible to tailor the biomimetic character of hydroxylapatite by modifications of its crystal chemistry (vacancies and ionic substitutions), trying to match that of natural bone tissues. For this purpose, the authors investigated by ab initio quantum mechanics within density functional theory the structural, electrostatic potential features and water adsorption process on the (001) surfaces of mixed type A-B carbonate-substituted hydroxylapatite. The provided data are comparable to previous experimental and preliminary theoretical one on hydroxylapatite, and further extend the knowledge of the modulation of the water molecule adsorption onto carbonated hydroxylapatite caused by the CO32- substitutions.