ISSN:
1662-9752
Quelle:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Thema:
Maschinenbau
Notizen:
Calcium phosphates with different Ca/P molar ratio can be obtained depending theprecipitation conditions such as pH and temperature. In this work the effect of the pH’s variationduring the H3PO4 addition in the synthesis of hydroxyapatite-HA, (Ca/P molar ratio 1.67)by neutralization method, was studied. The H3PO4 addition’s rate was 1.0, 1.5, 8.0 mL.min-1and in other experiment the H3PO4 was added at a time. After the addition was completed thepH ranged from 7-12. The suspensions were kept during 24 hours for ripening. The precipitatewas separated from the suspension by vacuum filtration, washed with distilled water anddried at 70ºC/24h. Afterwards the materials were analyzed by thermogravimetric analysis(TGA) with heating rate of 10°C/min in air. The calcination of the powders was accomplishedat 800ºC/3h with heating rate of 10ºC.min-1. The powders were characterized by X-ray diffraction(XRD), infrared spectrometry (FTIR), specific surface area (BET), and scanning electronmicroscopy (SEM). The results indicated that the ratio of addition of the acid can influenceboth the morphology and the formation of the phases (HA and TCP) in the obtainedpowders
Materialart:
Digitale Medien
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/14/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.530-531.593.pdf
