超声场中湿法制备Al2O3纳米粉工艺研究

STUDY ON THE TECHNOLOGY OF PREPARING Al_2O_3 NANO-POWDER BY WET CHEMICAL METHOD IN SUPERSONIC FIELD

研究了超声场下湿法制备纳米Al2O3粉体的工艺，探讨了超声对颗粒的形成和团聚的影响。讨论了不同超声频率对粉体团聚的影响。研究表明，超声能量能加速前驱体的成核，超声分散可控制晶核的长大和团聚；超声振动还能影响陈化过程中的沉淀向凝胶的转变，并可适当增大凝胶孔径从而减小毛细管力，获得颗粒充分分散，而且不包含较多包藏水和牢固吸附水的疏松三维网络状结构。这样的凝胶结构有利于最后得到疏松、少（无）团聚的纳米粉体。

A technique of preparing nano Al 2O 3 powder by wet chemical method in supersonic field was studied, the effects of supersonic radiation on the formation and reunite of the grains were discussed, and the influence of different supersonic frequency on the agglomerate of the powder was researched. The results show that supersonic energy can accelerate up the nucleation of the precursor, supersonic dispersion can control the growth and agglomerate of the crystal nucleus, supersonic vibration can also affect the process of the preparation translating into gel during the process of aging, broaden the pore diameter of the gel to decrease the capillary force to get a loossen 3D network of well dispersed grains without much contained water or firm absorbed water. This kind of structure of gel is easy to form agglomeration of the nano powder.