Paper Title:
Effect of pH Values on Conversion of Calcite Crystals into Calcium Phosphate Phases in Buffer Solutions
  Abstract

Calcium phosphate phases with laminar-plate structure were converted from calcite powders after soaking in phosphate buffer solutions of pH’s 6.0-8.0 at 37 °C for 9 days. The effect of pH values on the conversion of calcite crystals was investigated by X-ray diffraction, scanning electron microscopy and Fourier-transform infrared spectroscopy. If the pH value of a buffer solution is kept at 6.0, calcite powders are converted mainly to dicalcium phosphate dehydrate (DCPD) or octacalcium phosphate (OCP). If the pH value is kept at 6.4 or 7.0, calcite powders are converted mainly to OCP. Hydroxyapatite (HAP) with poorly crystalline can be obtained from calcite powders both by treatment of a basic buffer solution, and by treatment of an acid buffer solution without regulating its pH value during the reaction. The conversion mechanism of calcite crystals is a dissolution-precipitation reaction.

  Info
Periodical
Key Engineering Materials (Volumes 353-358)
Edited by
Yu Zhou, Shan-Tung Tu and Xishan Xie
Pages
2183-2186
DOI
10.4028/www.scientific.net/KEM.353-358.2183
Citation
Y. P. Guo, B. Q. Li, Y. Zhou, D. C. Jia, "Effect of pH Values on Conversion of Calcite Crystals into Calcium Phosphate Phases in Buffer Solutions", Key Engineering Materials, Vols. 353-358, pp. 2183-2186, 2007
Online since
September 2007
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$32.00
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