非水解溶胶-凝胶法合成堇青石的反应过程研究

发布时间：2018-02-28 01:43

  本文关键词： 堇青石 合成 非水解溶胶-凝胶法 反应过程 热膨胀系数　出处：《中国陶瓷》2017年04期 　论文类型：期刊论文

【摘要】：以自制乙醇铝,正硅酸乙酯和醋酸镁为前驱体,采用非水解溶胶-凝胶法合成堇青石,利用XRD、FT-IR和DTATG研究了醋酸镁的加入时机对堇青石合成的影响,前驱体的反应历程和凝胶加热过程中的相转变历程。结果表明:醋酸镁在铝、硅缩聚反应之后引入更利于合成堇青石;非水解溶胶-凝胶法合成堇青石的前驱体反应过程为:首先自制乙醇铝与正硅酸乙酯发生脱醚非水解缩聚反应形成含Al-O-Si键合的中间产物,然后醋酸镁进一步与之发生脱酯的非水解缩聚反应形成Mg-O-Al和Mg-O-Si键合。以醋酸镁为镁源非水解溶胶-凝胶法可在900℃形成μ-堇青石,μ-堇青石于1050℃转变为α-堇青石,并在1200℃制得α-堇青石纯相;由其制得陶瓷烧结体的热膨胀系数为1.329×10~(-6)/℃,具有良好的低膨胀特性。
[Abstract]:Cordierite was synthesized by non-hydrolytic sol-gel method with self-made aluminum ethanolates, ethyl orthosilicate and magnesium acetate as precursors. The effect of addition time of magnesium acetate on the synthesis of cordierite was studied by XRDD-FT-IR and DTATG. The reaction mechanism of the precursor and the phase transition in the gel heating process. The results show that magnesium acetate is more favorable for the synthesis of cordierite after the Polycondensation reaction of aluminum and silicon. The precursor reaction process of unhydrolyzed sol-gel synthesis of cordierite is as follows: firstly, self-made aluminum ethanol and ethyl orthosilicate deether non-hydrolytic Polycondensation to form intermediate product containing Al-O-Si bond. Then the unhydrolytic Polycondensation of magnesium Acetate with magnesium Acetate was carried out to form Mg-O-Al and Mg-O-Si bonds. Using magnesium acetate as the source of non-hydrolysis sol-gel method, 渭 -cordierite was formed at 900 鈩，

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