Nano zinc borate as a lubricant additive

Abstract

Lubricants consist of base oils and chemical additives such as dispersants, surfactants, oxidation inhibitors, and antiwear agents. Organic and inorganic boron-based additives increase wear resistance and decreases friction. Hexagonal boron nitride and metal borates are used for this purpose. Zinc borate is a synthetic hydrated metal borate. The production techniques of zinc borate generally include the reaction between zinc source materials (zinc oxide, zinc salts, zinc hydroxide) and the boron source materials (boric acid and borax). The nano zinc borate particles were prepared from zinc nitrate and borax in the present study by using low initial zinc and borate concentrations and low temperature to prevent particle growth. The templates span 60 and PEG 4000 were used to control the particle size. The particles were separated from mother liquor by centrifugation, washed with ethanol, dried and ground and used as additive to base oil. The particles have H2O and B(3)-O vibrations in their FTIR spectra. The empirical formula of the nanoparticles was approximately 3ZnO.2B2O3.4H2O from EDX and TGA analysis. X-ray diffraction diagram indicated the particles were in amorphous state. When the nanoparticles were added to light neutral oil the wear scar diameter and friction coefficient was lowered 50% and 20% respectively.