Ning C Q, Greish Y, El-Ghannam A
Center for Biomedical Engineering, University of Kentucky, Lexington, KY 40506, USA.
J Mater Sci Mater Med. 2004 Nov;15(11):1227-35. doi: 10.1007/s10856-004-5677-9.
Silica and calcium phosphates (CaP) are the most important ingredients in bioactive materials that bond to bone and enhance bone tissue formation. In this study, silica-calcium phosphate (SiO2-CaP) composites were developed by powder metallurgy method, using silica (SiO2) and anhydrous dicalcium phosphate (CaHPO4) powders (CaP) in the ratios (wt%): 20/80, 40/60, 60/40 and 80/20. The effects of temperature and chemical composition on crystallization and phase transformation of the SiO2-CaP composites were evaluated by XRD and FTIR. Thermal treatment of the starting material suggested that CaHPO4 transforms into: gamma-Ca2P2O7 at 800 degrees C; beta-Ca2P2O7 at 1000 degrees C and alpha-Ca2P2O7 at 1200 degrees C. On the other hand, beta-quartz was the only detected phase after thermal treatment of silica in the temperature range 800-1200 degrees C. For all SiO2-CaP composites, SiO2 and CaP did not modify the crystallization behavior of each other when sintered in the temperature range 800-1000 degrees C. However, at 1200 degrees C, CaP promoted the transformation of gamma-quartz into alpha-cristobalite. Moreover, SiO2 stabilized beta-Ca2P2O7. The modifications in the crystallization behavior were related to ion substitution and formation of solid solutions.
二氧化硅和磷酸钙（CaP）是生物活性材料中最重要的成分，它们能与骨骼结合并促进骨组织形成。在本研究中，采用粉末冶金法制备了二氧化硅-磷酸钙（SiO₂-CaP）复合材料，使用的二氧化硅（SiO₂）和无水磷酸二钙（CaHPO₄）粉末（CaP）的比例（重量百分比）分别为：20/80、40/60、60/40和80/20。通过XRD和FTIR评估了温度和化学成分对SiO₂-CaP复合材料结晶和相变的影响。对起始材料的热处理表明，CaHPO₄在800℃时转变为γ-Ca₂P₂O₇；在1000℃时转变为β-Ca₂P₂O₇；在1200℃时转变为α-Ca₂P₂O₇。另一方面，在800-1200℃温度范围内对二氧化硅进行热处理后，唯一检测到的相是β-石英。对于所有SiO₂-CaP复合材料，在800-1000℃温度范围内烧结时，SiO₂和CaP彼此不改变对方的结晶行为。然而，在1200℃时，CaP促进了γ-石英向α-方石英的转变。此外，SiO₂稳定了β-Ca₂P₂O₇。结晶行为的改变与离子取代和固溶体的形成有关。
