采用由环己烷、聚乙二醇辛基苯基醚(TritonX-100)、正丁醇与水溶液构成的反相微乳液体系,合成了纳米Al2O3粉体.采用X射线衍射、扫描电子显微镜、透射电子显微镜、比表面积分析仪等表征手段,分别对产物的结构、形貌、比表面积和孔容进行了表征,该纳米Al2O3比表面积约450m2·g^-1(随反应参数不同发生变化),均属γ-Al2O3,粒径均匀,颗粒直径小于10nm.考察了微乳液体系中水与表面活性剂的物质的量之比r0、表面活性剂与助表面活性剂的体积比φ、焙烧温度等关键因素对产物比表面积等物理性质的影响.结果表明,当r0=20,φ=0.5,焙烧温度为500℃时,可以得到大比表面积、高孔容、分散性好及粒径分布均匀的γ-Al2O3粉体.
Al2O3nanoparticles were prepared by reverse microemulsion method that uses cyclohexane,polyethylene glycol octylphenyl ether(TritonX-100),n-butylalcohol,and water.The structure,morphology,and specific surface area of the nano-alumina particles were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and specific surface area analysis.The specific surface area of the nano-alumina particles was about 450 m2·g-1(changing with different reaction parameters) and the crystal structure was γ-Al2O3.The particle size was smaller than 10 nm and very uniform.The effect of molar ratio of water to surfactant(r0),volume ratio of surfactant to assistant-surfactant(φ),and calcination temperature(T) on the characteristics of the product were studied.The results indicated that the nano Al2O3 powder with a high specific surface area,high pore volume,good dispersibility,and narrow particle size distribution was obtained at r0=20,φ=0.5,and T=500 ℃.