HAp/SiO_2复合陶瓷材料的制备及体外生物活性

Preparation and property characterizations of HAp-5.0wt%SiO_2 bioceramic composites

HAp和SiO2的混合粉末压制成型后,在1200℃下烧结得到含5.0%(质量分数)SiO2的HAp/SiO2生物陶瓷复合材料。烧结体的XRD及FT-IR分析结果表明,SiO2的添加促进了HAp发生热分解。其主要物相为α-TCP、HAp、Ca2P2O7以及生物玻璃(bioglass,BG)等。体外生物活性实验结果显示,样品浸泡在模拟体液(SBF)中24h后,表面出现花瓣状磷灰石沉积物,72h后进而生成板状沉积物,120h后在样品表面覆盖了较厚的类骨磷灰石层,经XRD测试分析表明,该层主要为碳酸羟基磷灰石(HCA)。制备的HAp-5.0%(质量分数)SiO2生物陶瓷复合材料具有比纯HAp更加优越的体外生物活性,可期待作为一种新的骨修复材料。

HAp-5wt%SiO2 bioceramic composites were prepared successfully by sintering the powders of hydroxyapatite（HAp） mixed directly with additive of 5.0wt%SiO2 at 1200℃.XRD and FT-IR analyses of the sintered samples demonstrate that the SiO2 additive promotes the thermal decomposition of HAp.The major phase compositions of the HAp/SiO2 composite consist of α-TCP,HAp,Ca2P2O7,bioglass（BG）,and etc.The in vitro bioactivity assessments show that the petal-like apatite sediments appear on the surface of the sample after soaking for 24h in stimulated body fluid（SBF）,and the plate sediments form as the soaking time is increased to 72h.After further immersing up to 120h,the sample surface is fully covered by a thicker bone-like apatite layer.XRD analyses indicate that the apatite layer is mainly composed of hydroxycarbonate apatite（HCA）,which is the major inorganic component of the human bone.As compared with pure HAp,the synthesized HAp-5wt%SiO2 bioceramic composite has a superior in vitro bioactivity,and it can be expected to act as a potential material for bone repair.