Synthesis of hydroxyapatite powders via mechanical activation technique
| dc.contributor.author | Omar, Zarina | |
| dc.date.accessioned | 2014-11-04T02:50:27Z | |
| dc.date.available | 2014-11-04T02:50:27Z | |
| dc.date.issued | 2007 | |
| dc.description | Master | en_US |
| dc.description.abstract | A preliminary experiment on low-speed ball-milling was carried out using calcium pyrophosphate and calcium carbonate (Ca2P2O7 – CaCO3) as starting materials with an addition of some amount of distilled water to produce hydroxyapatite (HA), Ca10(PO4)6(OH)2. The mixtures were milled for 8 hours using two equipment i.e. millingmixer and roll-mill. The milled mixtures were subsequently calcined at 1100 °C and was found that both methods successfully formed a single-phase HA. A more detailed study of the same mixtures but with mechanical activation being effected using a high-speed planetary ball-mill for different milling durations, calcination temperatures and milling cycles. The phase changes after each milling condition were analysed by x-ray diffraction (XRD) before and after calcination. Thermogravimetry and differential scanning calorimetry (TG/DSC) were conducted on the as-milled samples to determine the thermal behavior upon heating. Other analysis was also carried out such as particle size analysis, x-ray fluorescence (XRF) and fourier transformation - infra red (FT-IR) spectroscopy. Phase transformations were found to take place upon milling to produce a few intermediate phases other than the starting materials, which were finally transformed to a single-phase or mixed HA upon calcination. It was found that the optimum calcination temperature is influenced by the milling duration as well as the milling cycle. The lowest calcination temperature obtained in this work to form a single-phase hydroxyapatite (HA) is 900 oC after 6 hours milling using a cycle of 30 minutes milling and 2 minutes pause. This is obviously a significant improvement to the current status in forming a single-phase HA, which requires a calcination temperature of 1100 oC after 8 hours of milling. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/344 | |
| dc.language.iso | en | en_US |
| dc.subject | Materials and Mineral Resources Engineering | en_US |
| dc.subject | Hydroxyapatite powders | en_US |
| dc.subject | Mechanical activation technique | en_US |
| dc.title | Synthesis of hydroxyapatite powders via mechanical activation technique | en_US |
| dc.type | Thesis | en_US |
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