Nano-TiO2 powder which can be used to improve the abrasion resistance of lubricating oil has been studied.Hydrolysis precipitation method was used to prepare nano-TiO2 powder,and the influence of pH condition on the preparation of the nano-particles was studied.The samples were characterized by XRD and TEM,and it was found that pH=9.0 is the optimal acid-base environment of the reaction in this study.Oleic acid was used to perform the surface modification of nano-TiO2,it was found that the dispersibility in...