氧供体醇对非水解溶胶-凝胶法低温合成钛酸铝的影响

以TiCl4和无水AlCl3为原料,以无水低碳醇为氧供体通过非水解溶胶-凝胶法低温合成了钛酸铝,研究了无水低碳醇种类及用量对钛酸铝合成反应的影响.结果表明:当氧供体按反应式化学计量比用量加入时,在750℃能合成出钛酸铝,其中以乙醇的合成效果最好,异丙醇次之,正丁醇的效果较差;采用甲醇和叔丁醇作氧供体,由于它们的化学活性过大而引发水解反应,不能低温(750 ℃)合成钛酸铝.当醇用量超过化学计量比时,则合成效果显著下降;当醇用量低于化学计量比时,改变乙醇的用量对合成效果影响不明显,而减少异丙醇和正丁醇用量可显著提高钛酸铝的合成效果.

EFFECT OF OXYGEN DONOR ALCOHOLS ON LOW TEMPERATURE NONHYDROLYTIC SOL-GEL SYNTHESIS OF ALUMINUM TITANATE

Aluminum titanate has been synthesized at low temperature by nonhydrolytic sol-gel route using titanium tetrachloride and anhydrous aluminum trichloride as raw materials and anhydrous alcohols as oxygen donors. The effects of different anhydrous alcohols and their quantities on the low temperature synthesis of Al2TiO5 were studied. The results show that while the oxygen donor used is in stoichiometric ratio for synthesizing Al2TiO5 at 750 ℃, ethanol is the most effective oxygen donor, followed by isopropanol;n-butyl alcohol is a less effective oxygen donor. In contrast, Al2TiO5 can not be synthesized at low temperatures using methanol or tert-butyl alcohol as oxygen donor due to their high chemical reactivity resulting in hydrolysis reaction. When the quantities of alcohols added exceeding the stoichiometric, the effect on synthesis declined dramatically. However, use of less than the stoichiometricquantity of isopropanol and n-butyl alcohol led to the remarkable enhancement effect in the synthesis of Al2TiO5, but no obvious influence was observed when ethanol was used.