The synthesis and application of nano-scale TiO_2 attract interest in materials research. And the nano- scale TiO_2 can be used widely in many fields such as photocatalst,sterilization,environment et al. Because ultrafine TiO_2 is strong polarity material, the nano-scale TiO_2 can not be dispersed in non-polarity solvent well and is easy to agglomerate in the polarity solvent. In order to improve the dispersity in the polarity or non-polarity solvent, surface treatment of ultrafine tiania is ne...