Tribological Properties of Two Bis(trifluoromethylsulfonyl)imide-Based Ionic Liquids on Steel-Steel Contact

• Published in: Tribology transactions Vol. 57; no. 4; pp. 637 - 646
• Main Authors: López Sánchez, Fernando, Otero, Inés, López, Enriqueta R., Fernández, Josefa
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 04-07-2014; Taylor & Francis Inc
• Subjects: Boundary Lubrication Friction; Boundary Lubrication Wear; Friction; Ionic Liquids; Ions; SEM; Spectrum analysis; Steel; Temperature; Tribology; XPS
• ISSN: 1040-2004; 1547-397X
• DOI: 10.1080/10402004.2014.893475

The ionic liquids 1-butyl-1-methylpyrrolidinium bis(tri-fluoromethylsulfonyl)imide, [C
4
C
1
Pyrr][Tf
2
N], and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, [C
4
C
1
C
1
Im][Tf
2
N], were evaluated as neat lubricants for steel-steel sliding contacts using a ball-on-plate reciprocating tribometer under loads of 8, 18, and 30 N at room temperature conditions. A formulated semisynthetic oil was used for comparison. The best tribological behavior (friction coefficient and wear volume) was obtained with [C
4
C
1
C
1
Im][Tf
2
N] regardless of the load applied. Scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis showed the presence of tribolayers containing fluorides on the lubricated metal surface produced by weak tribochemical reactions.