Gradual Replacement of Ca2+ with Mg2+ Ions in Brushite for the Production of Ca1−xMgxHPO4·nH2O Materials

The present study investigates the gradual replacement of Ca2+ with Mg2+ ions in brushite (CaHPO4·2H2O). To date, this approach has not been systematically explored and may prove beneficial for production Ca1−xMgxHPO4·nH2O materials tailored properties which are suitable environmental medical applications. For their production, solutions sodium dihydrogen orthophosphate dehydrate, NaH2PO4·2H2O, calcium nitrate tetrahydrate, Ca(NO3)2·4H2O, magnesium hexahydrate, Mg(NO3)2·6H2O ammonium hydroxide solution, NH4OH, were used. At low Mg/Ca molar ratios (up to 0.25) starting partial Ca Mg takes place (Mg doping) but no struvite is produced as discrete phase. When ratio increases gradually 1.5, addition Mg-doped brushite, struvite, NH4MgPO4·6H2O, precipitates. microstructure different degrees analyzed depth use powdered XRD (X-ray diffraction), XPS photoelectron spectroscopy), thermogravimetric (TG) analysis SEM (scanning electron microscopy). results that solution can be monitored such a way composition obtained.