Synthesis of hydrophobic zinc borate nanodiscs for lubrication

The crystal and hydrophobic zinc borate (Zn2B6O11 center dot 3H(2)O) nanodiscs were successfully prepared by a wet method using Na2B4O7 center dot 10H(2)O and ZnSO4 center dot 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 (M), 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 Zn2B6O11 center dot 3H(2)O samples were hydrophobic. It had been found that the as-prepared materials displayed nanodisc morphology with average diameters from 100 to 500nm and the thicknesses about 30nm. Moreover, the friction coefficient of the base oil was decreased by the addition of hydrophobic zinc borate nanodiscs. (c) 2006 Elsevier B.V. All rights reserved.