Synthesis of calcium phosphate/calcium sulphate powder

DIP-COATING SENYAWA KALSIUM FOSFAT DARI BATU KAPUR BUKIT TUI DENGAN VARIASI RATIO MOL Ca/P MELALUI METODE SOL-GEL

“…Kalsium fosfat (CaP) merupakan suatu subjek yang menarik dari beberapa penelitian ilmiah dikarenakan aplikasinya yang luas sebagai pengganti tulang dan gigi dalam bentuk keramik dan polimer matriks komposit (Chong Liang et al, 2004). Penelitian ini dilakukan pemanfaatan batu kapur dengan mengolahnya menjadi bahan baku pada sintesis kalsium fosfat yaitu sebagai sumber kalsium.…”

Nano-beta-tricalcium phosphates synthesis and biodegradation: 1. Effect of microwave and SO 4 2− ions on β-TCP synthesis and its characterization

“…It is hard to eliminate the HA phase when the Ca/P molar ratio increased above 1.5, Therefore, the Ca/P ratio of the initial reagents had to be decreased below 1.5. More HPO 2− 4 ions incorporated in the CDHA lattice could be regulated by decreasing pH, synthesis temperature and initial Ca/P molar ratio (Kwon et al 2003, Raynaud et al 2002, Liang et al 2004, Vallet-Regi et al 1997, Destainville et al 2003 during the precipitation process.…”

“…The crystallite size of heat-treated β-TCP at 900 • C increased over the dried CDHA samples. Liang et al (2004) reported that calcium pyrophosphate (CPP) induced the decomposition of CaSO 4 and resulted in the formation of β-TCP according to reaction (5). This reaction is accelerated by increasing the calcination temperature to 1100 • C (Liang et al 2004).…”

“…Recent studies attempted to manifest the transformation of calcium deficient hydroxyapatite (CDHA; Ca 10−x (HPO 4 ) x (PO 4 ) 6−x (OH) 2 : 0 < x < 1) to β-TCP since it cannot be synthesized directly in aqueous solution (Liou and Chen 2002, Raynaud et al 2002, Kannan et al 2005, Gibson et al 2000, Tas et al 1997, Siddharthan et al 2005. Such transformation depends on the degree of calcium deficiency present in the assynthesized CDHA (i.e., the x value or the amount of HPO 2− 4 introduced into the CDHA lattice structure) (Liang et al 2004, Vallet-Regi et al 1997. Apatitic tricalcium phosphate Ca 9 (HPO 4 )(PO 4 ) 5 (OH) compound with a Ca/P molar ratio equal to 1.5 may precipitate instead of CDHA when its x value is equal to unity Chen 2002, Raynaud et al 2002).…”

“…It is well known that the phase purity of β-TCP is an important factor for successful bone generation (Peters and Reif 2004). The increase of the x value to reach unity is controlled by decreasing the pH value which accelerates the incorporation of HPO 2− 4 into the CDHA structure (Liang et al 2004). The Ca/P ratio of the precipitated powders increased when the synthesis temperature is above 30 • C (Raynaud et al 2002) along with increased ripening time (Destainville et al 2003) leading to a lower x value.…”