工艺因素对非水解溶胶-凝胶法制备钛酸铝纳米粉体的影响

Effect of Processing Factor on Preparation of Aluminium Titanate Nanopowder by Non-hydrolytic Sol-gel Method

以无水三氯化铝和四氯化钛为前驱体,正丁醇为氧供体,选择聚乙二醇(PEG)为分散剂,采用非水解溶胶-凝胶法(NHSG),低温合成钛酸铝纳米粉体。借助XRD、FT-IR、TEM等测试技术研究了反应前驱体浓度、凝胶化工艺以及PEG的加入顺序对钛酸铝纳米粉体合成及分散效果的影响。结果表明:随着前驱体浓度的减小,氯化醇盐之间的异质聚合反应变弱,导致钛酸铝合成效果的变差,但粉体团聚程度有减小的趋势,优选的前驱体浓度为2.25mol/L;与直接干燥、回流、容弹三种凝胶化工艺相比,回流结合容弹的凝胶化工艺因有助于形成更多的Al-O-Ti异质键合,因此具有更好的合成效果;在回流后加入PEG1000,既可保证钛酸铝的低温合成,又可抑制粉体的团聚,有利于制备分散性好、合成率高的钛酸铝纳米粉体。

Aluminum titanate nanopowder was prepared by the nonhydrolytic sol-gel method（NHSG） at low temperature,using anhydrous aluminum chloride and titanium tetrachloride as precursors,butanol as oxygen donor,polyethylene glycol（PEG） as dispersant.The influence of precursor concentrations,different gelation processes and PEG adding sequence on the synthesis and dispersion of aluminum titanate nanopowder was also studied by XRD、FT-IR and TEM.The results show that as the precursor concentration decreasing,the systhesis of aluminum titanate becomes worse due to the weaker heteropolycondensation reaction between chloroalkoxides,nevertheless,the aggregation of powders has the tendency to reduce,and the optimum precursor concentration is 2.25 mol/L;Compared with the gelation processes of direct drying,refluxing or auxiliary pressure field,the gelation process of refluxing combined with auxiliary pressure field results in better synthesis of aluminum titanate because of the easy formation of more Al-O-Ti heterobonding;Adding PEG after refluxing treatment not only guarantees the low-temperature synthesis of aluminum titanate,but also suppresses the powder aggregation,which contributes to the preparation of aluminum titanate nanopowder with good dispersion and high synthesis rate.