Table 8.
Typical reactions of preparation of CaP coating by ED [170–173].
| 2H2O + O2 + 4e− → 4OH− | (1) |
| 2H2O + 2e− → H2 + 2OH− | (2) |
| 2H+ + 2e− → H2 | (3) |
| NO32− + H2O + 2e− → NO2− + 2OH− | (4) |
| H2PO4− + H2O + 2e− → H2PO3− + 2OH− | (5) |
| H2PO4− + OH− → HPO42− + H2O | (6) |
| HPO42− + OH− → PO43− + H2O | (7) |
| H2PO4− ↔ HPO42− + H+ | (8) |
| HPO42− ↔ PO43− + H+ | (9) |
| 2H2PO4− + 2e−→ 2HPO43− + H2 | (10) |
| H2PO4− + 2e− → PO43− + H2 | (11) |
| Overall reactions: | ||
| Ca2+ + HPO42− + 2H2O → CaHPO4·2H2O | (DCPD) | (12a) |
| 8Ca2+ + 6HPO42− + 5H2O → Ca8H2(PO4)6·5H2O | (OCP) | (12b) |
| 3Ca2+ + 2PO42− + nH2O → Ca3(PO4) ·nH2O | (TCP) | (12c) |
| 10Ca2+ + 6PO43− + 2OH− → Ca10(PO4)6(OH)2 | (HA) | (12d) |