Mechanochemical Synthesis of SiO44--Substituted Hydroxyapatite, Part I - Kinetics of Interaction between the Components

• Published in: European journal of inorganic chemistry Vol. 2014; no. 28; pp. 4803 - 4809
• Main Authors: Chaikina, Marina V., Bulina, Natalya V., Ishchenko, Arcady V., Prosanov, Igor Yu
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.10.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Doping; Hydroxyapatite; Kinetics; Mecha­nochemical synthesis; Silicon; Solid-phase synthesis
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201402247

The kinetics of the room‐temperature dry mechanochemical synthesis of hydroxyapatite modified by SiO44– ions has been studied for the first time. The changes in the composition of the reaction mixture as a function of the time of mechanical activation in a planetary ball mill as well as the composition of the final product have been investigated by X‐ray phase analysis and IR spectroscopy. Certain stages of the interaction of the reactants have been analyzed with the help of high‐resolution electron microscopy. The mechanochemical synthesis conducted in air is accompanied by the incorporation of carbonate ions into the apatite lattice, which results in the formation of B‐type carbonated hydroxyapatite. The apatite structure starts to form after 5 min of mechanochemical activation of the reaction mixture, and the final single‐phase nanocrystalline powder of silicate‐substituted carbonated hydroxyapatite is formed after 30 min of activation. The kinetics of the dry mechanochemical synthesis of hydroxyapatite modified by SiO44– ions is studied. From the first seconds of mechanical activation, the initial Ca(H2PO4)2·H2O partially reacts with CaO to form CaHPO4 (interior of the nanoparticles); the nanoparticle shell is Ca(H2PO4)2·H2O, and the material located near the nanoparticles is a mechanical mixture of the initial components.