Table 1.
Name | Chemical formula | Symbol | Ca/P ratio | −log(Ksp) at 298 K |
---|---|---|---|---|
Monocalcium phosphate monohydrate | Ca(H2PO4)2·H2O | MCPM | 0.5 | 1.14 |
Dicalcium phosphate anhydrous | CaHPO4 | DCPA | 1.0 | 6.90 |
Dicalcium phosphate dihydrate | CaHPO4·2H2O | DCPD | 1.0 | 6.59 |
Octocalcium phosphate | Ca8H2(PO4)6·5H2O | OCP | 1.33 | 96.6 |
Hydroxyapatite | Ca10(PO4)6(OH)2 | HA | 1.67 | 116.8 |
Fluorapatite | Ca10(PO4)6F2 | FA | 1.67 | 120.0 |
Monocalcium phosphate anhydrous | Ca(H2PO4)2 | MCPA | 1.67 | 1.14 |
α-Tricalcium phosphate | α-Ca3(PO4)2 | α-TCP | 1.5 | 25.5 |
β-Tricalcium phosphate | β-Ca3(PO4)2 | β-TCP | 1.5 | 28.9 |
Tetracalcium phosphate | Ca4(PO4)2O | TTCP | 2.0 | 38.0 |
The parameter −log(Ksp) denotes the solubility product. The lower the −log(Ksp) value, the higher is the solubility. Similarly, it can also be noted that acidic products (MCPM) with lower Ca/P ratio have higher solubility compared to basic compounds, such as hydroxyapatite with higher Ca/P ratio.