CaO-SiO_2-P_2O_5-H_2O系统中CBC材料的溶胶凝胶过程研究 Ⅰ溶胶的形成及溶胶凝胶转变过程

STUDIES OF THE SOLGEL PROCESS OF CHEMICALLY-BONDED CERAMICS DEVELOPED IN THE CaO-SiO 2-P 2O 5-H 2O SYSTEM Ⅰ SOL FORMATION AND SOL-GEL TRANSITION PROCESSES

以溶胶凝胶方法制备ＣａＯＳｉＯ２Ｐ２Ｏ５Ｈ２Ｏ系统中ＣＢＣ材料的工艺流程为基础，利用ＸＲＤ，ＩＲ及固体核磁共振（２９Ｓｉ，３１ＰＮＭＲ）等测试方法研究了溶胶的形成及溶胶凝胶转变过程中的物相变化及物相间发生的化学反应。结果表明：在多组分溶胶的形成过程中，由Ｃａ（ＮＯ３）２·４Ｈ２Ｏ和Ｈ３ＰＯ４反应生成Ｃａ２Ｐ２Ｏ７和Ｃａ１０（ＰＯ４）６（ＯＨ）２（羟基磷灰石，简写为ＯＨＡｐ，下同），两者均在硅溶胶颗粒的表面上析晶长大；在多组分溶胶凝胶的转变过程中，发生失水，减少电解质，改变ｐＨ值等一系列现象。

From the sol gel synthesis process of the chemically bonded ceramics developed in the CaOSiO 2P 2O 5H 2O system,the main reactions taking place during the multicomponent sol formation and sol gel transition processes were revealed by XRD,IR and 29 Si, 31 P NMR.It is shown that during the former process,Ca 2P 2O 7 and Ca 10 (PO 4) 6(OH) 2(hydroxylapatite,abbreviated to OHAp)are synthesized from the reactions between Ca(NO 3) 2 ·4H 2O and H 3PO 4,which depositing on the surface of silica sol;during the latter process,a series of phenomena such as evaporation of water and electrolyte,variation in pH value take place.