| Effects of pH and reaction temperature on hydroxyapatite powders synthesized by precipitation |
In‑Ho Lee1, Jung‑A Lee2, Joon‑Hyung Lee2, Young‑Woo Heo2, Jeong‑Joo Kim2
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1Department of Engineering Technology, Graduate School of Industry, Kyungpook National University, Daegu 41566, Republic of Korea
2School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea |
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Received: October 11, 2019; Revised: November 6, 2019 Accepted: November 7, 2019. Published online: January 31, 2020. |
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| ABSTRACT |
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Hydroxyapatite (HA) was synthesized through the precipitation method and different processing parameters (Ca/P molar ratio, pH, and reaction temperature) were varied to investigate their influence on the HA formation. No HA powder was obtained at pH 10 and 25 °C, even when using a Ca/P ratio as high as 2.2. However, HA powders were successfully produced at pH above 11, 25 °C, and Ca/P ratio of 2.2. At pH 10 and 25 °C, the concentration of the H+ ions in the reaction solution increased and so did the Ca loss, resulting Ca-deficient hydroxyapatite (CdHA) formation. While HA was formed instead due to a lower Ca loss when the pH was increased to 11 and 11.3. As the reaction temperature was increased to 70 and 90 °C, the HA formation occurred regardless of the pH because of the decreased solubility of HA in the solution. |
| Key words:
Hydroxyapatite · Precipitation · pH · Temperature · Shape |
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