干燥技术在制备纳米粉体中的应用

The Application of Drying Techniques to Prepara Nanoscale Powder

由于纳米粒子的表面效应,用湿法制备出的纳米粉体的前躯体在干燥过程中极易形成团聚,已经不能采用传统的干燥方法。根据粉体干燥的理论,阐述了纳米粉体干燥过程的团聚机理,综述了微波干燥法、超临界干燥法、冷冻干燥法、共沸蒸馏法、喷雾干燥法等在制备纳米粉体中的应用,并指出了各种方法的优缺点。

Due to the surface effect of nanoscale particle,the precursor of nanoscale powder prepared by wet process can form aggregation easily, and so cannot be dried by usual techniques. In this paper, the mechanism of aggregation of nanoscale particles during drying process was described based on the theory of drying colloid, and the application of such techniques as microwave drying, supercritical fluid drying, freezing drying, azeotropic distillation and spray pyrolysis drying to the preparation of nanoscale powder were summarized, and the advantages and disadvantages of these methods were presented.