Ionic liquid lubricants: designed chemistry for engineering applications.

This tutorial review outlines current state of the art research on ionic liquid lubricants. Ionic liquids (ILs) were first reported as very promising high-performance lubricants in 2001 and have attracted considerable attention in the field of tribology since then because of their remarkable lubrication and anti-wear capabilities as compared with lubrication oils in general use; in recent times we have seen dramatically increased interest in the topic. The review starts with a brief introduction to ILs and fluid lubrication, and then discusses in more detail the tribological properties of IL lubricants, either as lubrication oils, additives or thin films. As well as lubrication mechanisms, some current problems and potential solutions are tentatively discussed.

[1]  Martin Priest,et al.  Tribological properties of ionic liquids as lubricants and additives. Part 1: Synergistic tribofilm formation between ionic liquids and tricresyl phosphate , 2008 .

[2]  H. Kondo Protic Ionic Liquids with Ammonium Salts as Lubricants for Magnetic Thin Film Media , 2008 .

[3]  Feng Zhou,et al.  Tribological performance of phosphonium based ionic liquids for an aluminum-on-steel system and opinions on lubrication mechanism , 2006 .

[4]  W. R. Carper,et al.  Molecular modeling of ionic liquid tribology: Semi-empirical bonding and molecular structure , 2007 .

[5]  Qunji Xue,et al.  Room temperature ionic liquid 1-ethyl-3-hexylimidazolium-bis(trifluoromethylsulfonyl)-imide as lubricant for steel–steel contact , 2004 .

[6]  María-Dolores Bermúdez,et al.  Ionic liquids as lubricants for steel–aluminum contacts at low and elevated temperatures , 2007 .

[7]  Feng Zhou,et al.  Benzotriazole as the additive for ionic liquid lubricant: one pathway towards actual application of ionic liquids , 2006 .

[8]  M. Forsyth,et al.  A Potential Novel Rapid Screening NMR Approach to Boundary Film Formation at Solid Interfaces in Contact with Ionic Liquids , 2008 .

[9]  F. J. Carrión,et al.  1-N-alkyl -3-methylimidazolium ionic liquids as neat lubricants and lubricant additives in steel–aluminium contacts , 2006 .

[10]  Laigui Yu,et al.  Room-temperature ionic liquids: a novel versatile lubricant. , 2001, Chemical communications.

[11]  Feng Zhou,et al.  Effect of the functional groups in ionic liquid molecules on the friction and wear behavior of aluminum alloy in lubricated aluminum-on-steel contact , 2005 .

[12]  Ugo Bardi,et al.  Interaction Between an Imidazolium Based Ionic Liquid and the AZ91D Magnesium Alloy , 2007 .

[13]  Wenjie Zhao,et al.  Nano/Microtribological Properties of Ultrathin Functionalized Imidazolium Wear-Resistant Ionic Liquid Films on Single Crystal Silicon , 2008 .

[14]  A. Pensado,et al.  The Pressure–Viscosity Coefficient of Several Ionic Liquids , 2008 .

[15]  B. Bhushan,et al.  Nanotribological and nanomechanical properties of lubricated PZT thin films for ferroelectric data storage applications , 2008 .

[16]  B. Bhushan,et al.  Ultrathin Wear‐Resistant Ionic Liquid Films for Novel MEMS/NEMS Applications , 2008 .

[17]  C. Kajdas Importance of anionic reactive intermediates for lubricant component reactions with friction surfaces , 1994 .

[18]  Alan R. Kennedy,et al.  Ionic liquid crystals: hexafluorophosphate salts , 1998 .

[19]  Feng Zhou,et al.  High-Temperature Tribological Properties of 2-Substituted Imidazolium Ionic Liquids for Si3N4-Steel Contacts , 2008 .

[20]  J. Richard,et al.  Formation and stability of N-heterocyclic carbenes in water: the carbon acid pKa of imidazolium cations in aqueous solution. , 2004, Journal of the American Chemical Society.

[21]  Wei-min Liu,et al.  Tribological properties of ultra-thin ionic liquid films on single-crystal silicon wafers with functionalized surfaces , 2006 .

[22]  Feng Zhou,et al.  Tribological evaluation of α, ω-diimidazoliumalkylene hexafluorophosphate ionic liquid and benzotriazole as additive , 2008 .

[23]  Peng Wang,et al.  Tribological Performance of Room-Temperature Ionic Liquids as Lubricant , 2002 .

[24]  Feng Zhou,et al.  Functional Room-temperature Ionic Liquids as Lubricants for an Aluminum-on-Steel System , 2004 .

[25]  B. Bhushan,et al.  AFM-based nanotribological and electrical characterization of ultrathin wear-resistant ionic liquid films. , 2008, Journal of colloid and interface science.

[26]  Ichiro Minami,et al.  The Tribological Properties of Ionic Liquids Composed of Trifluorotris(pentafluoroethyl) Phosphate as a Hydrophobic Anion , 2008 .

[27]  M. Masuko,et al.  Tribological Characteristics of Imidazolium-based Room Temperature Ionic Liquids Under High Vacuum , 2007 .

[28]  M. Bermúdez,et al.  Imidazolium ionic liquids as additives of the synthetic ester propylene glycol dioleate in aluminium–steel lubrication , 2008 .

[29]  Feng Zhou,et al.  Bisimidazolium ionic liquids as the high-performance antiwear additives in poly(ethylene glycol) for steel-steel contacts. , 2009, ACS applied materials & interfaces.

[30]  Tom Welton,et al.  Room-temperature ionic liquids: solvents for synthesis and catalysis. 2. , 1999, Chemical reviews.

[31]  F. J. Carrión,et al.  Room temperature ionic liquids as lubricant additives in steel–aluminium contacts: Influence of sliding velocity, normal load and temperature , 2006 .

[32]  Ichiro Minami,et al.  Thermo‐oxidative stability of ionic liquids as lubricating fluids , 2007 .

[33]  Feng Zhou,et al.  Tribological properties of plasma nitrided stainless steel against SAE52100 steel under ionic liquid lubrication condition , 2006 .

[34]  M. Bermúdez,et al.  Surface interactions and tribochemical processes in Ionic Liquid lubrication of aluminium-steel contacts , 2007 .

[35]  Chengfeng Ye,et al.  Polyethylene glycol functionalized dicationic ionic liquids with alkyl or polyfluoroalkyl substituents as high temperature lubricants , 2006 .

[36]  J. Shreeve,et al.  Phosphazene-based ionic liquids: synthesis, temperature-dependent viscosity, and effect as additives in water lubrication of silicon nitride ceramics. , 2004, Inorganic chemistry.

[37]  Zhuo Zeng,et al.  Polyfluoroalkyl, Polyethylene Glycol, 1,4-Bismethylenebenzene, or 1,4-Bismethylene-2,3,5,6-Tetrafluorobenzene Bridged Functionalized Dicationic Ionic Liquids: Synthesis and Properties as High Temperature Lubricants , 2008 .

[38]  J. Zabinski,et al.  Ionic Liquid Lubrication Effects on Ceramics in a Water Environment , 2004 .

[39]  Kenneth R. Seddon,et al.  Ionic liquids. Green solvents for the future , 2000 .

[40]  Min Zhu,et al.  Effect of the Anion on the Tribological Properties of Ionic Liquid Nano-Films on Surface-Modified Silicon Wafers , 2008 .

[41]  John J. Truhan,et al.  Ionic liquids with ammonium cations as lubricants or additives , 2006 .

[42]  Wei-min Liu,et al.  Preparation and Characterization of New Phosphonyl‐Substituted Imidazolium Ionic Liquids , 2004 .

[43]  M. Bermúdez,et al.  Effect of ionic liquid on the structure and tribological properties of polycarbonate–zinc oxide nanodispersion , 2007 .

[44]  K. R. Seddon,et al.  Applications of ionic liquids in the chemical industry. , 2008, Chemical Society reviews.

[45]  Qunji Xue,et al.  Effect of tetraalkylphosphonium based ionic liquids as lubricants on the tribological performance of a steel-on-steel system , 2007 .

[46]  S. Sasaki,et al.  Tribological properties of Fe7Mo6-based alloy under two ionic liquid lubrications , 2008 .

[47]  Wei-min Liu,et al.  Preparation of functional ionic liquids and tribological investigation of their ultra-thin films , 2006 .