Aqueous Synthesis of Calcium Phosphate Bioceramics

Low temperature hydrothermal synthesis of calcium phosphate ceramics: Effect of excess Ca precursor on phase behavior

Asep Sofwan Faturohman Alqap^b & Iis Sopyan*

^bMechanical Engineering Program, Faculty of Engineering, University of Bengkulu, Jalan Raya Kandang Limun, Bengkulu 38000, Indonesia

Received 31 July 2009; revised 20 October 2009 and accepted 20 October 2009

Low temperature hydrothermal exchange reaction has been used to synthesize calcium phosphate materials comprising hydroxyapatite and β-tricalcium phosphate using CaO and NH₄H₂PO₄ as calcium and phosphorus precursors respectively. The effect of excess of calcium precursor on phase behavior of these materials has been investigated by varying CaO content (0, 10 and 20 mole% excess of 0.1 mole CaO) in the suspension stirred at 90 ºC. The as synthesized paste has been dried followed by calcination at 700-1200 ºC. Results show the formation of Ca-deficient apatite at the lower calcination temperature. Excess of CaO shifts the balance to hydroxyapatite formation at the higher calcination temperature such that β-tricalcium phosphate, β-tricalcium phosphate + hydroxyapatite and hydroxyapatite of higher purity are obtained with 0, 10 and 20 mole% excess CaO, respectively.

Keywords: Hydrothermal synthesis, CaO excess, Hydroxyapatites, β-Tricalcium phosphates, Calcium deficient apatites, Calcination, Ceramics, Calcium phosphates

Full article can be accessed from Indian Journal of Chemistry section A,

IJC-A Vol.48A(11), November 2009. http://nopr.niscair.res.in/handle/123456789/6462