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

This study was carried out to investigate the effect of a complete exchange of Ca2+ with Zn2+ ions on the structure of brushite (CaHPO4.2H(2)O), which might be advantageous in the production process of CaxZn1-xHPO4.nH2O. To acquire the starting solutions needed for the current study, (NH4)2HPO(4), Ca(NO3)(2).4H(2)O, and Zn(NO3)(2).6H(2)O 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 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.

Automated summary

This study investigated the effect of completely exchanging Ca2+ ions with Zn2+ ions on the structure of brushite. The results showed that Ca is partially substituted by Zn when the Zn/Ca ratio is below 0.25 and that Zn doping hinders brushite crystallization. Increasing the Zn/Ca ratio led to the formation of biphasic compounds and different minerals. Adjusting the Zn/Ca ratio in the starting solution can be used to obtain minerals with specific compositions, allowing for the production of biomaterials with desired characteristics.