超细CeO2粉体在醇水混合介质中的超声分散行为

摘要

通过测定20nm、200nm、500nm和5μmCeO2粉体在醇水混合介质中的粒度分布、表面电性及分散稳定性,研究了不同粒径级别超细CeO2粉体在体积比为1∶1的醇水系悬浮液中的超声分散行为。实验结果表明：在一定超声功率和超声频率下,不同粒径级别醇水系CeO2悬浮液均存在最佳超声时间。不同粒径级别醇水系CeO2悬浮液的表面电性各不相同;纳米级和亚微米级CeO2在醇水中所带Zeta电位为正值,微米级CeO2的Zeta电位为负值,悬浮液中CeO2粉体的平均粒度越大,其电位绝对值越小。不同粒径级别醇水系CeO2悬浮液的分散稳定性能各不相同;从超声结束后的分散效果来看,亚微米CeO2粉体在醇水混合介质中的分散性能最好;从多个沉降时间段内的稳定性来看,纳米CeO2粉体在醇水混合介质中的稳定性能最好。%Ultrasonic dispersion behavior of CeO2 powder in ethanol-water solution(1∶1 in volume) was studied by measuring the particle size distribution,the surface potential and the dispersion stability of the CeO2 with average particle size of 20nm,200nm,500nm and 5μm,respectively.At certain ultrasonic power and frequency,an optimum ultrasonic operation time can be picked up for the CeO2 of each particle size.The surface potential was not identical,but different with different particle size.The Zeta potential of nanometer or submicron CeO2 was positive,while that of micron CeO2 turned out to be negative.The bigger the average particle size of CeO2 powder was,the smaller the absolute value of its Zeta potential would be.The dispersion ability and stability of the CeO2 powders in the ethanol-water solution are different for different particle size.In the sight of the dispersion ability right after the ultrasonic dispersion,the submicron CeO2 powder was the best,and in the sight of the suspension stability during their sedimentation period,the nanometer CeO2 powder was the best.