Ceramics Based on Brushite Powder Synthesized from Calcium Nitrate and Disodium and Dipotassium Hydrogen Phosphates

Abstract

Brushite (CaHPO₄ · 2H₂O) powder has been synthesized in aqueous 1.0 M solutions of calcium nitrate dipotassium hydrogen phosphate, and disodium hydrogen phosphate at a Ca/P ratio of unity, without adjusting the pH of the reaction. After synthesis and drying, the fraction of a reaction by-product (NaNO₃, KNO₃, or their mixture) in the powder was about 20 wt %. After firing at temperatures from 800 to 1000°C, the ceramics prepared using the powder synthesized from Ca(NO₃)₂ and Na₂HPO₄ consisted of β-Ca₂P₂O₇ and β-NaCaPO₄. After firing at temperatures from 900 to 1100°C, the ceramics prepared using the powder synthesized from Ca(NO₃)₂ and K₂HPO₄ consisted of Са₁₀К(РО₄)₇ and СаК₂Р₂О₇. The ceramic composites produced in this study can be recommended as materials for resorbable bone implants.