基于薄膜技术制备超细片状氧化铝的研究

Preparation of Ultrafine Lamellate Alumina Powder via Chemical Route

结合薄膜涂布技术,在超声波的作用下,利用溶胶-熔盐复合工艺制备超细片状氧化铝。以硫酸铝钾和氯化钾混合溶液中的KAl(SO_4)_2·12H_2O为铝源,KCl为熔盐,加入Na_2CO_3溶液,经超声处理,制成铝溶胶,并将溶胶涂布在水溶性树脂基底上。洗脱后的片状氢氧化铝经高温煅烧,成为厚度均一、表面光滑的超细片状氧化铝。研究熔盐比例,添加剂种类和含量,超声波处理时间对粉体形貌的影响。扫描电镜及X射线衍射分析结果表明:铝源与熔盐比例为1∶4,添加剂为TiO_2及含量为2%,超声处理时间为30 min,1200℃高温煅烧条件下得到形貌规则,表面光滑,粒径在10μm以下,径厚比10左右的超细六角片状ɑ-氧化铝。

The coatings of ultrafine laminate alumina grains were synthesized via chemical route.First,Al2O3-sol was prepared with materials,including KAI(SO4)2·12H2O,molten KCl,TiO2 and Na2CO3;next,the ultrasonic dispersed Al2O3-sol was roll-coated on the PET membrane pre-covered with soluble resin,and the Al2O3/PET composite membrane formed after microwave baking;and finally,Al2O3 powder was produced by calcining the eluted Al(OH)3coatings at 1200℃for 2h The influence of the variables,including the molar-ratio of reactants,TiO2-content and dispersion time on the shape/size of Al2O3 grains was investigated with X-ray diffraction and scanning electron microscopy.The results show that hexagonal lamellate α-Al2O3 grains,with average grain-size of 10μm and aspectratio of 10,were fabricated under the optimized condition:Al-source to KCl molar-ratio of 1:4,TiO2-content of 2%, ultrasonic dispersion time of 30 min and calcination temperature of 1200℃.