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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备纳米氧化铝粉体。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。
Using aluminum isopropoxide as raw material, HNO3, NH4OH and NH4HF2 were selected as sols, and nano-alumina powder was prepared by sol-gel technique. The effects of several peptizing agents on the properties of nano-alumina powder were studied by means of SEM, TEM and XRD powder analysis and characterization. The results show that the addition of different kinds and amounts of sols during the hydrolysis of aluminum isopropoxide will greatly affect the morphology, particle size and dispersibility of nano-alumina powders. Particle size analysis shows that the particle size of the nano-alumina powder prepared when HNO3, NH4HF2 or NH4OH is added into aluminum isopropoxide hydrolysates is a parabola with a maximum point. XRD analysis showed that the sol had no effect on the crystalline form of the powder. Scanning electron microscopy and transmission electron microscopy analysis showed that different sols have a great influence on the morphology and dispersion of nano-alumina powder. When ammonia is used as the sol-gel, the powder is flocculent and agglomeration is serious. As the sol, the dispersibility of the powder is greatly improved, the agglomeration of the bulk is not obvious, but the powder morphology is irregular; with ammonium bifluoride as the sol, the granularity is obvious, the dispersion is good, no agglomeration appears .