均匀设计在微乳液法制备纳米氧化铝中的应用

对多因素的复杂实验体系，均匀设计法能在不降低交互作用敏感性分析的前提下，可通过较少的实验次数获得可靠的数学模型，高效优化出最佳工艺条件。本文采用优化组合的U₁₂₊（6^6）均匀设计试验方案，考察了微乳液法制备纳米氧化铝前体的工艺条件，获得了氧化铝粉体的粒径与铝盐浓度、沉淀剂浓度、反应温度、表面活性剂与助表面活性剂的体积比、油相与表面活性剂的体积比5个关键因素之间的数学模型。利用该数学模型优化出的最佳制备工艺条件，制备出了氧化铝前体，该前体经1180℃焙烧，转晶为α-Al₂O₃粉体。α-Al₂O₃的一次粒子形状为棒状，一次粒子的Scherrer粒径为30nm左右，二次粒子的粒径D₅₀为760nm。

Application of uniform design in the preparation of nano-alumina by microemulsion method

For complex systems with multiple influence factors, reliable mathematical models could be obtained with few experiments by using the uniform-design method without decreasing interaction-sensitivity analysis, which can ben then used to derive the opitmal process conditions. A U₁₂₊ (6^6) uniform-design test scheme was employed to investigate the optimum process conditions for preparing nano-alumina-precursor by microemulsion method. According to the experimental results, the mathematical model for relationship between the particle size of nano-alumina and the 5 factors of the concentration of aluminum salt, the precipitant concentration, the reaction temperature, the volume ratio of surfactant to cosurfactant, and the volume ratio of oil to surfactant, repsectively, was established. By using the mathematical model established, the optimum process conditions for preparing nano-alumina precursor were given. The α-Al₂O₃ powder was then obtained by calcination at 1180℃ from the nano-alumina precursor preprared under the optimum process conditions. For the α-Al₂O₃ powder, the primary particle shape was rod, the primary particle size was about 30nm, and the secondary particle size (D₅₀) was 760nm.