KEYWORDS

Thermal Properties, Thin Film Lubrication, Adsorption, Surface Energy, FTIR, TG/DTA

NEWLY-SYNTHESIZED THERMALLY-STABLE IONIC LIQUIDS AS FRICTION MODIFIERS FOR CARBON-COATED MEDIA

To avoid adhesion-related problems, lubrication has to be achieved using a molecularly-thin lubricant film for magnetic thin film media. Liquid lubricants have the advantage that they will creep across the surface to replenish a portion of the layer which has been removed by abrasion. However, because of their mobility, liquid lubricants may suffer the disadvantage of spinning off from the disk surfaces during operation, especially at the higher operating temperatures.  Preliminary results from our studies have shown the potential for using ionic liquids as a new class of thermally-stable lubricants. An octadecyl ammonium salt with pentadecafluoro-octanate significantly reduces the friction compared to the corresponding amide and Z-DOL. We also found that the friction and thermal degradation decreases with the increasing delta pKa between the acid and the base composing the ILs. In this study, a series of ILs including the dicationic and dianionic types were synthesized by changing the acid and base structures and the effect of their molecular structures on the frictional and thermal properties was investigated.

AUTHORS

Hirofumi Kondo, Kouki Hatsuda, Nobuo Tano, Makiya Ito, Kyungsung Yun, Takeshi Noguchi,  Dexerials Corporation, Kanuma, Japan and Masayoshi Watanabe, Yokohama National University, Yokohama, Japan