Ionic Liquids as Novel Lubricants

The rapid growth in ionic liquids research has resulted in the development of a number of new ionic liquids, as well as many associated applications. At present, ionic liquids have been widely used as "green solvents" replacing traditional organic solvents for organic synthesis, catalysis, separation, etc. Ionic liquids have attracted considerable attention as a potential, high performance and versatile lubricants because they have characteristic of low melting point, low vapor pressure, adjustable polarity, safety and stability. This review describes in detail the recent developments of ionic liquids as high performance lubricant additives on the tribology, including pure ionic liquids as conventional lubricants, combination of ionic liquids and other additives as lubricants, ionic liquids as additives in conventional lubricating materials and ionic liquids as lubricants in micro/nanoelectrical mechanical systems. Some current problems of ionic liquids as high performance lubricants are also discussed and analyzed. Finally, the research thought and application outlook of ionic liquids as lubricants on the tribology are prospected.