Preparation and Surface Modification SiO2 Nano-Powder with Antifriction Properties

Abstract

In this paper, ethyl silicate as the main raw material, SiO₂ was prepared by precipitation method. The powder was in situ surface modification, get a small particle size and stability in the lubricating oil, monodisperse spherical SiO₂ nanoparticles. Using X-ray diffraction analysis, infrared spectroscopy, laser particle size analysis, scanning electron microscopy and other methods to characterize them. The study results showed that the optimal solution to preparate of SiO₂-situ surface modification of nano-powder is ethanol as solvent, KH-560 as a surface modifier, the holding time of 3 h, the temperature was 80 °C. The resulting average particle size of SiO₂ nanoparticles is 91 nm and uniform, as regular sphere. It can be obtained by the infrared spectrum that KH-560 bonded with the SiO₂ nanoparticles via a covalent bond, organic coating layer formed on the surface, the SiO₂ nanoparticles changes from hydrophilic oleophobic to lipophilic hydrophobic. The amount of the powder added to lubricating oil as anti-wear agents, the long grind four-ball friction test, study its antifriction properties. The results showed that SiO₂ nanoparticles are added to the lubricating oil has obvious antifriction effect, and the optimal dosage is 0.1 wt %.