Facile Synthesis of Molybdenum Disulfide Micro-Spheres and the Tribological Properties in Liquid Paraffin

Abstract

Well-dispersed MoS₂ micro-spheres with the diameters of 0.5∼1.5 µm have been successfully synthesized via the extraction-solvothermal method. The ions were extracted into hexane by the extractant Cyanex 302 (di-(2,4,4-trimethylpentyl) monothiophosphinic acid) firstly, then the extracted solution was given solvothermal treatment to synthesize MoS₂ at 150 °C for 24 hours. The obtained samples was characterized by XRD, EDS, SEM, TEM, and HRTEM technologies, respectively. Results indicated that Cyanex 302 acted as phase transferring agent, reductant, sulfur source and morphology-controlling agent in the whole procedure. Moreover, the tribological properties of liquid paraffin (LP) containing the as-prepared MoS₂ micro-spheres were also evaluated on a four-ball machine and the chemical states of some typical elements on the worn surfaces were examined with XPS, showing that the MoS₂ product was an excellent oil additive in LP with good anti-wear and friction-reducing properties.

Keywords:

• Cyanex 302
• extraction-solvothermal method
• micro-spheres
• MoS₂
• tribological properties

This work was financially supported by the foundation of Ph. D. subjects 2005, P. R. China (No. 20050426003). The authors thank Cytec Canada Inc. for its kindly supplying the extractant of Cyanex 302.