| Abstrakt: |
Abstract: The effect of three different initial alkaline pH values (pH= 8, 9 and 10) in synthesised hydroxyapatite (HA) via a wet chemical precipitation approach was investigated. Waste ark clam shells (ACS) were used in this work as a source of calcium oxide in order to utilise waste materials in the production of synthetic Hydroxyapatite (HA). The HA was treated at different sintering temperature from 200 to 1000°C to study the effect on the physical, the structural properties, the phase formation, the Vickers microhardness and the molar ratio of calcium to phosphate (Ca:P). From the results, the crystallite size and density of the HA obtained were increased as the sintering temperature increased. However, the appearance of biphasic HA and β-tricalcium phosphate (β-TCP) was detected at pH 9 with 1000°C, but did not occur at pH 8 and 10. In addition to the obtained results, it was clearly identified that the formation of β-TCP in the HA phase is related to the initial pH value, sintering temperature and Ca:P ratio. The Vickers microhardness showed that the single-phase HA was the hardest one compared to the biphasic HA/β-TCP. It shows the optimal value of the Vickers microhardness for the single-phase HA with a pH 10 at 1000°C is 4.15 MPa. |
