The Effect of Full-Scale Exchange of Ca2+ with Zn2+ Ions on the Crystal Structure of Brushite and Its Phase Composition

Abstract

This study was carried out to investigate the effect of a complete exchange of Ca2+ with Zn2+ ions on the structure of brushite (CaHPO4·2H2O), which might be advantageous in the production process of CaxZn1−xHPO4·nH2O. To acquire the starting solutions needed for the current study, (NH4)2HPO4, Ca(NO3)2·4H2O, and Zn(NO3)2·6H2O were utilized in several molar concentrations. The findings indicate that Ca is partly substituted by Zn when the Zn/Ca molar ratio is below 0.25 and that Zn doping hinders the crystallization of brushite. A continued increase in the Zn/Ca molar ratio to 1 (at which point the supersaturation of the Zn solution rises) led to a biphasic compound of monoclinic brushite and parascholzite precipitate. Elevating the Zn/Ca molar ratio to 1.5 resulted in a precipitate of a parascholzite-like mineral. Finally, increasing the Zn/Ca molar ratio to 4 and above resulted in the formation of the hopeite mineral. Future biomaterial production with specific and bespoke characteristics can be achieved by adjusting the Zn/Ca ratio in the starting solution. It Rhas been established that the Zn/Ca ratio in the starting solution can be adjusted to obtain minerals with specific compositions. Thus, new synthesis methods for parascholzite and hopeite were introduced for the first time in this manuscript.

Preparation and Characterization of Mono- and Biphasic Ca1−xAgxHPO4·nH2O Compounds for Biomedical Applications

“…Unfortunately, bone implants can be vulnerable to bacterial colonization in environments with reduced blood supply and local immunodeficiency, leading to postoperative infections that may require implant removal [22,23]. Metal ions, including Ag + , Cu 2+ , and Zn 2+ , are recognized as antimicrobial agents in CaPs [24][25][26]. Ag+ is particularly known for its antibacterial properties against various microorganisms, including antibioticresistant strains [27], demonstrating high antimicrobial activity with relatively low cytotoxicity [28,29].…”