Abstract: The CeO₂ sample was modified by the wet chemical method. The surface modification of nanometer cerium oxide power and the effect factors were studied; the optimum modifying agent and condition were found. Through orthogonal experiment, the optimum reaction conditions were obtained with: the amount of the stearic acid was 6%, pH was 8, the modified temperature was 70 ℃, modified time was 1.5 h. Using as modifying agent in the optimum condition, the lipophiiic degree of modified nanometer CeO₂ is 73.0%. Experimental results that nanometer cerium oxide powders are well dispersed after modification, the average particle size is little change before and after and agglomeration is significantly reduced.

Key words: Nano cerium dioxide, Surface modification, Stearic acid, Lipophilic degree

摘要： 采用湿法对纳米二氧化铈进行改性。研究了纳米CeO₂表面改性的影响因素，通过正交实验确定了最优改性剂和改性条件。改性剂硬脂酸的质量分数为6％、pH为8、改性温度为70 ℃、改性时间为1.5 h时，改性后的纳米CeO₂的亲油化度达到73.0％。结果表明，改性后的纳米二氧化铈粉体能够较好地分散于甲醇中，改性前后平均粒径大小变化不大，由TEM观察到团聚现象明显降低。

关键词: 纳米二氧化铈 , 表面改性 , 硬脂酸 , 亲油化度