Abstract
Wetting and dewetting phenomena generated on magnetic disks lubricated with PFPE having polar end groups were observed for different lubricant film thicknesses and its mechanism was clarified from the comparison with the spreading characteristics and surface energy variation depending on the film thickness. It is confirmed that the dewetting did not occur for one monolayer thickness, and evidently occurred for double and triple layered thicknesses. In addition, for a thickness thicker than a quadratic layered thickness, the dewetting did not occur for a short time range of a few days while it occurred for a longer time range of a few weeks. These characteristics were found to be well correspondent with the non-replenishment phenomenon arising in a lubricant depletion test, and well explained from the surface energy variation with increasing film thickness.
