The aluminium isopropoxide was used as raw materials and preparing nano alumina was carried out by sol-gel method in the paper. The effects of some parameters such as the amounts of the ethanol, the water and the hydrochloric acid on the efficiency of the reaction and on the size of composite particles were investigated in details. Moreover, the temperature was also discussed as a crucial factor. Based on the orthogonal test, the optimal variables were chosen to synthesize the nano alumina. The adsorption amount of different kinds of surfactants was tested, as well. It has been shown that it would be possible to synthesize nano alumina at 50 C for 3 h, and the optimal mole ratios of the variables were confirmed by orthogonal test. The adsorptions of nonionic surfactant and reactive anionic surfactant were fast, less than 60 min. The adsorption amount of anionic surfactant was more than nonionic, which was due to the surface of nano alumina presenting positive electricity.

The organic alkoxides including ethyl silicate, aluminium isopropoxide and butyl titanate were used as raw materials and preparing nano SiO 2 -Al 2 O 3 -TiO 2 particle by sol-gel method in the study. The influences of some determinant parameters such as the dosages of the ethanol, the water and the ammonia on the efficiency of the reaction and on the size of micro particles were investigated in details. In addition, the temperature was considered as one of the crucial factors. Moreover, the characters of nano particles were tested by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the nano SiO 2 -Al 2 O 3 -TiO 2 particle can be obtained at 55 C for 2 h, and the crystal form was Amorphous State. The optimal mole ratios of the variables were confirmed by orthogonal test. Based on the optimal variables, nano particles were synthesized. The morphology of the nano SiO 2 -Al 2 O 3 -TiO 2 particle investigated by TEM was random grain with the size of 20-50 nm.