Effect of pH control of mixture solution on the fabrication of the highly pure β-tricalcium phosphate powders synthesized by liquid–solid mixture precipitation method

Abstract

The β-tricalcium phosphate (β-TCP; Ca3(PO4)2) powders with high purity could be attained through mixing and precipitating (NH4)2HPO4 with solution state and Ca(NO3)2·4H2O with solid state and controlling the pH of mixture solution in a range from 7.0 to 8.5 within a short time. The FT-IR results showed that the peak of calcium pyrophosphate (Ca2P2O7) excluding the peaks associated with β-TCP appeared at a pH ranging from 5.0 to 7.0 but did not appear at a pH ranging from 7.0 to 8.5. It is considered that the phase purity of β-TCP powders could be significantly improved through liquid–solid mixture precipitation and pH control of mixture solution. The XRD and SEM results showed that the phase purity and the particle size of precipitated β-TCP powders were above 99% and ranged from 200nm to 600nm, respectively.