表面活性剂结构对纳米CeO2在水中的分散性影响

采用悬浮液体系吸光度法,研究不同结构表面活性剂对纳米CeO2粉体在水中分散性影响。考察了影响分散稳定性的物理分散方式、表面活性剂的结构和浓度等因素。结果表明,超声波分散效率远优于机械搅拌。表面活性剂作为纳米CeO2在水介质中的分散剂,其分散性与表面活性剂结构有重要关系。非离子型表面活性剂效果优于离子型表面活性剂。非离子型表面活性剂以亲油基团朝向CeO2粒子,且亲油基团链长较长的效果更好;而离子型表面活性剂以亲水基团朝向CeO2粒子,亲水基团小的表面活性剂效果好,亲油基团的链长度影响不太明显。

Influence of surfactant structure on dispersion of nano-CeO2 in water

The dispersion of nano-CeO2 powders was evaluated by measuring the absorbance of suspension system,and the effects of surfactants with different structures on the dispersion of nano-CeO2 powders in water were studied.The physical dispersion mode,the structure and concentration of surfactants were investigated.The results shown that the dispersing efficiency of ultrasonic wave was much better than that of mechanical stirring.Surfactant was a dispersant of nano-CeO2 in water,and its dispersibility was closely related to the structure of surfactant.The effect of nonionic surfactants was better than that of ionic surfactants.The effect of nonionic surfactants with lipophilic groups toward CeO2 particles was better than that of ionic surfactants with hydrophilic groups toward CeO2 particles.The effect of surfactants with small hydrophilic groups was better,and the chain length of lipophilic groups was not obvious.