The decomposition mechanisms of a perfluoropolyether at the head/disk interface of hard disk drives

The decomposition mechanisms of a perfluoropolyether (ZDOL) at the head/disk interface under sliding friction conditions were studied using an ultra-high vacuum tribometer equipped with a mass spectrometer. Chemical bonding theory was applied to analyze the decomposition process. For a carbon coated slider/CN(x) disk interface, the primary decomposed fragments are CFO and CF(2)O, caused by the friction decomposition and electron bombardment in the mass spectrometer. For an uncoated Al(2)O(3)-TiC slider/CN(x) contact, CF(3) and C(2)F(3) fragments appear in addition to CFO and CF(2)O, resulting from the catalytic reactions and friction decomposition, indicating that the decomposition mechanism associated with friction leads to the breaking of the main chain of ZDOL and forms CF(2)=O, which reacts with Al(2)O(3) to produce AlF(3), and the rapid catalytic decomposition of ZDOL on the AlF(3) surface follows. Moreover, the effects of frictional heat, tribocharge, mechanical scission and Lewis acid catalytic action, generated in friction process, on the decomposition of ZDOL are discussed.