Tribological properties of water-soluble TiO2 nanoparticles as additives in water

Purpose - The purpose of this paper is to prepare water-soluble TiO2 nanoparticles and evaluate the tribological properties as additives in water. Design/methodology/approach - Nanoparticles present excellent friction-reducing and antiwear properties as additives in base oils. However, there are seldom literatures about the nanoparticles as additives in water as yet. In this work, water-soluble TiO2 nanoparticles were prepared by sol-gel method and characterized with transmission electron microscopy and selected area electron diffraction. The tribological properties as additives in water were investigated by SRV and the surface analysis by scanning electron microscope and X-ray photon electron spectroscope. Findings - TiO2 nanoparticles modified with polyethylene glycol have uniform size about 10 nm and easily dissolve in water. The tribological experiments showed TiO2 nanoparticles exhibit excellent friction-reducing and antiwear properties. Research limitations/implications - The paper is restricted to only TiO2 nanoparticles. Some other water-soluble nanoparticles also should be prepared and their tribological properties investigated. Practical implications - Water-soluble TiO2 nanoparticles could be used as water additives and improve the tribological properties. Originality/value - This paper emphasises that the water-soluble nanoparticles are prepared and could be used as water additives.