Synthesis of hydrophobic zinc borate nanodiscs for lubrication

Abstract The crystal and hydrophobic zinc borate (Zn 2 B 6 O 11 ▪3H 2 O) nanodiscs were successfully prepared by a wet method using Na 2 B 4 O 7 ▪10H 2 O and ZnSO 4 ▪7H 2 O as raw materials in situ aqueous solution, and oleic acid as the modifying agent. The microstructures and morphology of the as-obtained samples were studied by X-ray diffraction (XRD), infrared spectra (IR), scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS) and thermogravimetric analysis (TGA). The measurement of the active ratio indicated that Zn 2 B 6 O 11 ▪3H 2 O samples were hydrophobic. It had been found that the as-prepared materials displayed nanodisc morphology with average diameters from 100 to 500 nm and the thicknesses about 30 nm. Moreover, the friction coefficient of the base oil was decreased by the addition of hydrophobic zinc borate nanodiscs.