Study of the Preparation of a Modified Lubricant Using a W/O Microemulsion Reactor and a Cyclic Voltammetry Study of Rubbing Steel S45C with Lubricants

Abstract

A successful preparation of a Schiff base copper complex was carried out directly in rap oil, using a W/O microemulsion reactor. The prepared Schiff base copper complex dispersed equably and spontaneously in the oil. Owing to a modification of the rap oil, by addition of 2%wt of Cu (II) chelate of bissalicylaldehyde-ethylenediamine, the friction coefficient decreased by 80% compared to that of the original one. It was verified by energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) analyses that steel/steel rubbing pairs underwent a selective transferring process with such modified lubricants. It was suggested that the mechanism for the improvement in the tribological characteristics of the modified lubricants was due to a selective transferring effect. The Cu (II) chelate of bissalicylaldehyde-ethylenediamine not only served as an additive in the rap oil, but also self-assembled on the surface of the 100Cr6 steel. The self-assembled monolayer (SAM) was examined using SEM techniques. The SAM was characterized with cyclic voltammetry (CV). It indicated that the SAM could activate the rubbing surface of 100Cr6 steel, which benefited the tribological chemical reaction.

Keywords:

• Cyclic voltammetry
• modified lubricant
• Schiff base copper complex
• selective transferring
• self-assembled monolayer
• W/O microemulsion reactor

Acknowledgments

The authors would like to thank NSFC (50775164) and GZ408 (303/6) for financial support, and would express their gratitude for partial financing support from Q200718004 and a strategy research grant number CityU7002595.