Effects of both Sr and Mg substitution on compositions of biphasic calcium phosphate derived from hydrothermal method

Abstract Biphasic calcium phosphate ( BCP ) ceramics have received much attention in the field of biomaterials. Regulation of phase compositions of BCP is extremely important for improving their bioactivity. In this study, the effects of Sr‐ and Mg‐addition on the phase composition and morphology of BCP ceramics, prepared by a conventional hydrothermal way, were investigated deeply. The results indicated that the addition of Sr and Mg both facilitated the generation of β‐tricalcium phosphate (β‐ TCP ), and the relationships between the addition and the relative content of β‐ TCP under different pH 8.5 and 10.5 were similar. The relative content of β‐ TCP phase increased linearly with the Sr addition. Meantime, the relative content of β‐ TCP changed quadratically with the Mg addition and reached its peak when the Mg addition was up to 30%. Besides, the fraction of β‐ TCP phase of samples synthesized at pH 8.5 was higher than that of samples synthesized at pH 10.5 when the substitution was same. The morphology did not change significantly in Sr‐substituted samples while an enhancement in density was observed with Mg addition in Mg‐substituted samples. These results and findings provide more comprehensive knowledge about controlling the phase compositions of BCP by changing the initial substitution of Mg and Sr.