非水解溶胶—凝胶法制备钛酸铝纳米粉体及稳定化的工艺研究

发布时间：2018-03-25 06:41

  本文选题：非水解溶胶-凝胶法　切入点：钛酸铝　出处：《景德镇陶瓷学院》2010年硕士论文

【摘要】： 本研究以无水三氯化铝和四氯化钛为前驱体,正丁醇为氧供体,采用非水解溶胶-凝胶法,创新性地运用回流结合容弹凝胶化工艺合成钛酸铝纳米粉体。借助XRD、SEM、TEM、FT-IR、DTA-TG等测试手段研究了不同凝胶化工艺、前驱体浓度、PEG的分子量(用量)及添加时机等工艺参数对钛酸铝的低温合成及其分散效果的影响;此外,对比分析了不同合成方法对钛酸铝陶瓷烧结性能的影响。 同时,还系统地对非水解溶胶-凝胶法制备的钛酸铝粉体进行了稳定化研究,借助FT-IR、XRD、DTA-TG、热膨胀仪等测试手段研究了铁、镁源种类及用量和镁源的加入时机等对低温稳定钛酸铝效果的影响,并对稳定钛酸铝的热膨胀特性及烧结性能进行了研究。 研究表明:回流及容弹凝胶化工艺条件下,较优的溶剂分别为三氯甲烷和二氯甲烷, PEG的引入会大大影响钛酸铝的低温合成效果;在回流结合容弹凝胶化的工艺条件下,前驱体浓度为2.25mol/L,在回流工艺之后容弹工艺之前引入占前驱体总质量3wt%的PEG1000,可合成出平均粒径为20-30nm的钛酸铝纳米粉体。钛酸铝凝胶中Al-O-Ti键的形成是非水解溶胶凝胶法能在750℃低温合成钛酸铝的关键;采用非水解溶胶-凝胶法回流结合容弹的凝胶化工艺制备的钛酸铝粉体烧结体的抗折强度高达18.3MPa,是固相法的6.3倍,水解法的2.5倍。 镁、铁的醇盐和其无水有机酸盐能在750℃低温下使铁、镁离子进入钛酸铝晶格,起到稳定钛酸铝的作用。镁铁复合掺杂稳定钛酸铝效果明显优于单一铁、镁掺杂,且固定掺杂量为20mol%(铁、镁掺杂量比例为1:1)时,稳定化效果最优,合成的钛酸铝粉体在1100℃保温80h不分解,热膨胀系数仅为-0.039×10-6/℃。镁源改性剂引入时机在铝、钛前驱体发生缩聚反应之后加入的稳定效果较优。
[Abstract]:In this study, anhydrous aluminum trichloride and titanium tetrachloride were used as precursors and n-butanol as oxygen donor. Aluminum titanate nanocrystalline powders were synthesized by refluxing and capacitive gelation process. Different gelation processes were studied by means of XRDX SEMX TEMT FT-IRT DTA-TG and so on. The effects of molecular weight (dosage) of precursor concentration of PEG and adding time on the low temperature synthesis and dispersion effect of aluminum titanate were studied, and the effects of different synthesis methods on sintering properties of aluminum titanate ceramics were compared and analyzed. At the same time, the stabilization of aluminum titanate powder prepared by non-hydrolytic sol-gel method was studied systematically. Iron was studied by means of FT-IRX XRDX DTA-TG, thermal expansion instrument, etc. The effects of the type and amount of magnesium source and the addition time of magnesium source on the effect of stabilizing aluminum titanate at low temperature were studied. The thermal expansion characteristics and sintering properties of stabilized aluminum titanate were also studied. The results show that the optimal solvents are trichloromethane and dichloromethane under the conditions of reflux and elastomeric gelation, and the introduction of PEG will greatly affect the low temperature synthesis of aluminum titanate, The concentration of precursor is 2.25mol / L, and PEG1000, which accounts for 3wt% of the total mass of precursor, is introduced before the reflux process. The formation of Al-O-Ti bond in aluminum titanate gel is unhydrolyzed sol-gel with the average particle size of 20-30nm. The key to the synthesis of aluminum titanate at 750 鈩，

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