Synthesis of Mg-substituted hydroxyapatite nanopowders: Effect of two different magnesium sources

Two different magnesium sources of magnesium nitrate and magnesium stearate were used to synthesize Mg-substituted hydroxyapatite (Mg-n-HA) nanoparticles by a co-precipitation method. The obtained produces were characterized using SEM, FTIR, XRD and TEM. It was revealed that two magnesium ions were both incorporated successfully in HA lattice by partially replacing calcium ion, noted as Mg-n-HA-1 and Mg-n-HA-2, respectively. There was no obvious difference of needle-like morphology, nanoparticles size and thermal stability among n-HA, Mg-n-HA-1 and Mg-n-HA-2. However, crystallinity in Mg-n-HA-2 was remarkably decreased. More importantly, the dispersibility of Mg-n-HA-2 in dichloromethane was greatly improved, as comparing to Mg-n-HA-1 and n-HA. The above results demonstrated that magnesium stearate was a better magnesium source to obtain Mg-n-HA than magnesium nitrate, which could effectively reduce the powder crystallinity and prevent the aggregation of Mg-n-HA nanoparticles resulting from the introduction of organic magnesium source.