Transfer layers: A comparison across SWNTs, DWNTs, graphite, and an ionic fluid

Abstract

Lubrication is the science of friction at moving interfaces. Nanomaterials acting as interfacial modifiers can minimize friction and thereby improve energy efficiency. To test this hypothesis, single- (SWNT) and double-walled (DWNT) carbon nanotubes and an ionic fluid are tested individually and compared to SWNTs and graphite as additives within the ionic fluid. The minimum coefficient of friction is correlated with the longest lifetime using a ball-on-disc tribometer, in air, at atmospheric pressure. Results are interpreted in terms of the nanotubes' mechanical properties and the formation of transfer layers upon the tribosurfaces. © 2011 Randy L. Vander Wal et al.