溶胶剂对纳米氧化铝粉体特性的影响

以异丙醇铝为原料,分别选用HNO3,NH4OH和NH4HF2作为溶胶剂,采用溶胶凝胶技术制各纳米氧化铝粉体.利用SEM,TEM和XRD等粉体分析和表征手段研究了几种胶溶剂对纳米氧化铝粉体特性的影响规律.结果表明,异丙醇铝水解时加入不同种类和不同量的溶胶剂将大大影响着纳米氧化铝粉体的形貌、粒径和分散性.粒度分析表明异丙醇铝水解时加入HNO3,NH4HF2或NH4OH时所制备的纳米氧化铝粉体的粒径大小与溶胶剂的关系曲线为具有一个最大值点的抛物线.XRD分析表明溶胶剂对粉体的晶型没有影响.扫描电镜和透射电镜分析表明,不同溶胶剂对纳米氧化铝粉体的形貌以及分散性有较大的影响,其中以氨水为溶胶剂时,粉体为絮状,且团聚现象严重;以硝酸为溶胶剂,粉体的分散性有较大提高,大块团聚现象不明显,不过粉体形貌不规则;以氟化氢铵为溶胶剂,颗粒性明显,分散性很好,无大块团聚出现.

Effect of the Peptizer on the Characteristics of Nanometer Alumina Powders

In this paper,nanometer alumina powders were prepared by sol-gel method using aluminium alkoxide as precursor and selecting HNO3,NH4OH and NHrHF2 as the peptizers,respectively.The effect of different peptizers on the characteristics of nanometer alumina powders was studied by SEM,TEM and XRD.The results showed that the morphology,particle size and dispersing of nanometer alumina powders were greatly influenced by adding different kinds of peptizers when aluminium alkoxide hydrolyzed.The particle size analysis results indicated the curve of the particle size-the peptizer content presented parabola with a maximum value when the peptizer was HNO3,NH4HF2 or NH4OH.XRD shows that the peptizer has no influence on the crystal structure of nanometer alumina.SEM and TEM observations show that nanometer alumina is floccule when the peptizer is NH4OH;nanometer alumina grains with the irregular shape appear and their dispersing is improved when the peptizer is HNO3;the dispersing of nanometer alumina powders is excellent when the peptizer is NH4HF2.