初始碳酸根含量和热处理对碳酸羟基磷灰石制备和性能的影响

EFFECT OF INITIAL CARBONATE CONTENT AND HEAT TREATMENTS ON PREPARATION AND PROPERTIES OF CARBONATED HYDROXYAPATITE

以湿化学法制备了不同碳酸根含量的碳酸羟基磷灰石(carbonated hydroxyapatite,CHA)。研究了热处理温度和气氛对这些CHA的烧结、热稳定性和碳酸根替代的影响。通过X射线衍射、Fourier变换红外光谱及热分析等多种测试手段表征了CHA粉体的特性。结果表明:CHA坯体的烧结温度和粉体的热稳定性与初始的碳酸根含量有关,含量越高,烧结温度越低,热稳定性越差。热处理过程中,CHA中碳酸根的替代量随热处理温度的升高而减少,并在热处理过程中A位的碳酸根较B位的碳酸根在更低的温度下失去。湿二氧化碳气氛能促进CHA的烧结,减少碳酸根的损失,提高热稳定性,有利于生成以B型替代为主的CHA。

Carbonated hydroxyapatite （CHA） with different carbonate contents were synthesized by wet-chemical method. Effects of heat treatment temperature and atmosphere on the sinter, thermal stability and carbonate substitution of CHA were investigated. The CHA powders were characterized by X-ray diffraction, Fourier transform infrared spectra and thermal analysis. The results showed that the sintering temperature and the thermal stability are related to the initial carbonate contents. As the initial carbonate contents increase, the sintering temperature decreases and the thermal stability deteriorates. In the heat treatments the carbonate substitution contents decreased as the heat treatment temperature increased and the carbonate ions substituted in the A sites of the apatite would be released at lower temperatures than those substituted in the B sites. A wet CO2 atmosphere can promote the sintering of the samples, decrease the carbonate loss from the material as well as increase the thermal stability. It also was favorable for obtaining CHA with prevailing B-type substitution.