Preparation and tribological performance of corncob-shaped nanospherical-Ni-BTC MOFs@HNTs nanocomposite towards friction improvement

The improvement of interface compatibility of nanomaterials as nanoadditives was conductive to raise the friction performances in oil. Herein, we successfully constructed a corncob-shaped Ni-BTC MOFs@HNTs nanocomposite through the controllable growth of nanospherical Ni-BTC MOFs on the external surface of HNTs nanotubes. The composition and structure of Ni-BTC MOFs@HNTs were determined by a catalog of characterization. Due to being the better interface compatibility of MOFs in organic compound, the existence of Ni-BTC MOFs on the external surface of HNTs evidently promoted the dispersibility of HNTs nanotubes in oil. The tribological behaviors of Ni-BTC MOFs@HNTs as nanoadditives in base oils were deeply studied by ball-on-ball contact friction. The experimental results showed that the average friction coefficient and wear scar diameter of Ni-BTC MOFs@HNTs -base oil were decreased by 39.7% and 29.4% at 0.04 wt% adding content relative to base oil, respectively. Meanwhile, the carrying capacity of Ni-BTC MOFs@HNTs-base oil was increased by 16.3%. Finally, the worn surfaces lubricated by Ni-BTC MOFs@HNTs-base oil were deeply characterized by a series of spectra analysis, thus revealing the synergistic lubrication effect of Ni-BTC MOFs and HNTs.