Preparation of Cu–Ni bimetallic nanoparticles surface-capped with dodecanethiol and their tribological properties as lubricant additive--颗粒学报PARTICUOLOGY

Chen, L., Xu, H., Cui, H., Zhou, H., Wan, H., & Chen, J. (2017). Preparation of Cu–Ni bimetallic nanoparticles surface-capped with dodecanethiol and their tribological properties as lubricant additive. Particuology, 34, 89-96. https://doi.org/10.1016/j.partic.2016.12.006

Preparation of Cu–Ni bimetallic nanoparticles surface-capped with dodecanethiol and their tribological properties as lubricant additive

Lei Chen, Haiyan Xu, Haixia Cui, Huidi Zhou, Hongqi Wan ^*, Jianmin Chen ^*

State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China

10.1016/j.partic.2016.12.006

Volume 34, October 2017, Pages 89-96

Received 11 July 2016, Revised 14 December 2016, Accepted 21 December 2016, Available online 18 May 2017, Version of Record 12 August 2017.

E-mail: wanhq@licp.cas.cn; chenjm@licp.cas.cn

Highlights

• Cu–Ni bimetallic nanoparticles surface-capped with dodecanethiol were successfully prepared.

• Cu–Ni bimetallic nanoparticles were highly hydrophobic and exhibited good dispersibility.

• As-prepared nanoparticles had excellent load-carrying, anti-wear and friction-reducing capacities.

• Mechanisms leading to the improvement of tribological properties were discussed.

Abstract

Cu–Ni bimetallic nanoparticles surface-capped with dodecanethiol were prepared via the controlled reduction of nickel nitrate and copper nitrate in the presence of dodecanethiol as ligand and hydrazine hydrate as reductant. The morphology and structure of the Cu–Ni nanoparticles were analyzed by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometry, and thermal gravimetric analysis. Furthermore, the tribological properties of the Cu–Ni nanoparticles as a lubricant additive in liquid paraffin were evaluated with a four-ball machine, and the morphology and elemental composition of the worn surfaces were analyzed by three-dimensional non-contact surface profilometry and X-ray photoelectron spectroscopy, respectively. The results indicated that Cu–Ni nanoparticles prepared at a sufficient dodecanethiol concentration showed almost no signs of aggregation, and exhibited good dispersibility in various apolar solvents. The addition of the Cu–Ni nanoparticles improved the load-carrying capacity as well as friction-reducing and anti-wear abilities of liquid paraffin, attributed to the rolling effect of agglomerated Cu–Ni nanocores released by the Cu–Ni nanoparticles during sliding, and the formation of a boundary lubricating film containing tribochemical reaction products such as iron oxides and iron sulfate.

Graphical abstract

Keywords

Cu–Ni bimetallic nanoparticles; Dodecanethiol; Surface capping; Tribological properties

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