Triboelectric charging of a perfluoropolyether lubricant

Perfluoropolyethers (PFPE) are used extensively to lubricate hard disks for high density information storage. Some PFPE lubricants have been shown to be vulnerable to dissociative electron attachment as well as electron bombardment. Triboelectric charges generated during sliding contact may generate quasi-free electrons capable of degrading the lubricant. We describe measurements of triboelectric charging in a model polymer-metal system with and without a PFPE lubricant and show that negative charge accumulates on the substrate polymer surface, both with and without the lubricant. In the presence of the lubricant, some of this charge moves through and becomes bound to the lubricant. Electron and positive ion emission from PTFE-lubricated surfaces during contact sliding again indicate motion of charge through the lubricant. Ion emission in particular suggests possible degradation of the lubricant. (C) 2003 American Institute of Physics.