CaO-MgO-P_2O_5-SiO_2-CaF_2系统自硬性玻璃的研究

为研究钙离子、镁离子在体内环境中对自硬性玻璃结晶行为的影响,为自硬性生物活性玻璃的临床应用提供依据,本文设计了CaO-P2O5-SiO2-CaF2(Ca-glass)和CaO-MgO-P2O5-SiO2-CaF2(CaMg-glass)系统玻璃并使用模拟体液(simulated body flu id,SBF)进行了研究。首先采用磷酸氢二氨(NH4)2HPO4]/NH4H2PO4]硬化液与Ca-glass、CaMg-glass制成硬化体,然后使用X射线衍射(XRD)、扫描电镜(SEM)、失重、力学分析等方法,研究硬化体在SBF中的结晶性、降解性和力学性能。实验结果表明,玻璃粉末与磷酸铵缓冲溶液反应形成了磷酸铵钙(NH4)2.Ca(HPO4)2.H2O]硬化体。硬化体经过SBF浸泡,Ca-glass系统硬化体中部分磷酸铵钙转化成羟基磷灰石,而CaMg-glass系统硬化体仍然为磷酸铵钙。Ca-glass与CaMg-glass硬化体在SBF中浸泡28天分别降解19.4%和31.3%,抗压强度分别为93.14MPa和64.52MPa。镁离子的歧化作用是导致Ca-glass、CaMg-glass硬化体结晶性能、降解性能以及力学性能差别的主要原因。

Study of CaO-MgO-P2 O5-SiO2-CaF2 Self-Hardening Glass

In order to provide the basis of clinical application for self-hardenning bioactive glass and investigate the effects of calcium and magnesium ions on crystallization behavior of the glasses in simulative body environment, the CaO-P2o5-SiO2-CaF2 （Ca-glass） and CaO-MgO-P2O5-SiO2-CaF2 （CaMg-glass） system bioglass was designed and studied using simulated body fluid （SBF）. Firstly, the hardening bodies were prepared by mixing hardening solution of composite ammonia phosphate （NH4 ） 2HPO4 ]/ NH4H2PO4 ] with Ca-glass or CaMg-glass powder comparatively. Then, the crystallinity, degradability and mechanical property were studied using _SBF solution diffraction （ XRD ） , scanning （ SEM ）, weightlessness and by means of X-ray electron microscopy mechanical analysis methods. The experimental results indicated that calcium ammonia phosphate （NH＋）2 · Ca · （HPO＋）2 · H2O] was formed after being mixed glass powder with composite ammonia phosphate solution. Immerging in SBF solution, the CaMg-glass hardening body was still consisted of calcium ammonia phosphate, while parts of the calcium ammonia phosphate in Ca-glass hardening body was transformed into hydroxyapatite crystal. The degradation ratios of Ca-glass and CaMg-glass hardening bodys were 19.4% and 31.3% after being immerged in SBF solution for 28 days, with compressive strength of 93.14 MPa and 64. 52 MPa respectively. The disproportionation of magnesium ions was the main reason for the differences of crystallinity and degradability as well as mechanical property between Ca-glass and CaMg-glass hardening bodies.