Graduate School of Engineering, Nagoya University, B2-3(611), Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan,
J Mater Sci Mater Med. 2011 Feb;22(2):209-16. doi: 10.1007/s10856-010-4201-7. Epub 2010 Dec 14.
Double-step hydrothermal processing is a process where powder compacts of calcium phosphates are exposed to vapor of solvent solution, followed by being immersed in the solution. In the present study, we investigated the effects of ammonium carbonate on formation of calcium-deficient hydroxyapatite (CDHA) through double-step hydrothermal processing. The synthesized CDHA has high crystallinity when the solution has relatively low concentration of the ammonium carbonate ranging from 0.01 to 0.25 mol dm(-3). Carbonate content in the prepared samples were distinctly increased with increasing the concentration of ammonium carbonate to indicate formation of carbonate-containing calcium-deficient hydroxyapatite (CHAp) with low crystallinity. Morphology of the CHAp formed on the compacts varied progressively from rods and rosette-like shape to irregular shape with increase in the initial concentration of the ammonium carbonate in the solution. Application of ammonium carbonate in the double-step hydrothermal processing allows fabrication of irregular-shaped CDHA containing carbonate ions in both phosphate and hydroxide site, with low crystallinity, when the initial concentration of ammonium carbonate was 0.5 mol dm(-3) and more.
两步水热法是一种将磷酸钙粉末压块暴露于溶剂蒸气中，然后再将其浸入溶液中的方法。在本研究中，我们通过两步水热法研究了碳酸铵对形成缺钙羟基磷灰石（CDHA）的影响。当溶液中碳酸铵的浓度相对较低（0.01 至 0.25 mol dm(-3)）时，合成的 CDHA 具有高结晶度。随着碳酸铵浓度的增加，样品中的碳酸盐含量明显增加，表明形成了结晶度较低的含碳酸根的缺钙羟基磷灰石（CHAp）。在压块上形成的 CHAp 的形态逐渐从棒状和玫瑰花样形状变为不规则形状，随着溶液中初始碳酸铵浓度的增加而变化。当碳酸铵的初始浓度为 0.5 mol dm(-3)及更高时，在两步水热法中应用碳酸铵可以制备含有碳酸根离子的不规则形状的 CDHA，其在磷酸盐和氢氧化物位均含有碳酸根离子，结晶度较低。
