Preparation of WS₂ nanocomposites via mussel-inspired chemistry and their enhanced dispersion stability and tribological performance in polyalkylene glycol

Abstract

A novel biomimetic surface modification method utilizing mussel-inspired chemistry was used to prepare tungsten disulfide (WS₂) nanocomposites, which enhanced the dispersion stability and tribological performance of WS₂ in polyalkylene glycol (PAG). Herein, WS₂-polydopamine-methoxypolyethylene glycol amine (WS₂-PDA-MPGA) was first synthesized via mussel-inspired chemistry and used as a lubricant additive in PAG. After modification, the dispersion stability of WS₂ nanosheets in PAG was obviously improved. Moreover, the tribological performance of WS₂-PDA-MPGA in PAG at high temperature was evaluated by the oscillating reciprocating tribometer. Compared to pure PAG, the lubricant composition containing WS₂-PDA-MPGA exhibited excellent performance in friction reduction and anti-wear properties at high temperature. The optimal tribological performance could be obtained when the percentage of additives was 0.9 wt%. The tribological results indicate that WS₂-PDA-MPGA, with its good dispersion stability, has better friction reduction and anti-wear properties than does WS₂ in PAG base oil. The chemical composition analysis of the wear surface indicated that a stable protective film had been formed by physical adsorption and tribo-chemical reactions. Therefore, the surface modification strategy is an effective way to improve the dispersion stability of WS₂ in PAG, which can be expanded application of WS₂ in the tribological field.

Graphical Abstract

Keywords:

• WS₂ nanocomposites
• mussel-inspired chemistry
• dispersion
• tribological performance

Acknowledgments

The authors are thankful for National Natural Science Foundation of China (NSFC 51475445 and 51775536).