Abstract
Despite excellent tribological behaviors of ionic liquids (ILs) as lubricating oils, their friction-reducing and anti-wear properties must be improved when they are used under severe conditions. There are only a few reports exploring additives for ILs. Here, MoS2 and WS2 quantum dots (QDs, with particle size less than 10 nm) are prepared via a facile green technique, and they are dispersed in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm]PF6), forming homogeneous dispersions exhibiting long-term stabilities. Tribological test results indicate that the addition of MoS2 and WS2 QDs in the IL can significantly enhance the friction-reducing and anti-wear abilities of the neat IL under a constant load of 500 N and a temperature of 150 °C The exceptional tribological properties of these additives in the IL are ascribed to the formation of protective films, which are produced not only by the physical absorption of MoS2 and WS2 QDs at the steel/steel contact surfaces, but also by the tribochemical reaction between MoS2 or WS2 and the iron atoms/iron oxide species.
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References
Palacio M, Bhushan B. A review of ionic liquids for green molecular lubrication in nanotechnology. Tribol Lett40: 247–268 (2010)
Zhou F, Liang Y M, Liu W M. Ionic liquid lubricants: designed chemistry for engineering applications. Chem Soc Rev38: 2590–2599 (2009)
Qu J, Truhan J J, Dai S, Luo H, Blau P J. Ionic liquids with ammonium cations as lubricants or additives. Tribol Lett22: 207–214 (2006)
Nancarrow P, Mohammed H. Ionic liquids in space technology-current and future trends. Chem Bio Eng Rev4(2): 106–119 (2017)
Zeng Z, Phillips B S, Xiao J C, Shreeve J M. 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. Chem Mater20: 2719–2726 (2008)
Wu X H, Liu J M, Zhao Q, Zhang M, Zhao G Q, Wang X B. In situ formed ionic liquids in polyol esters as high performance lubricants for steel/steel contacts at 300 °C. ACS Sustainable Chem Eng3: 2281–2290 (2015)
Ye C F, Liu W M, Chen Y X, Yu L G. Room-temperature ionic liquids: A novel versatile lubricant. Chem Commun21: 2244–2245 (2001)
Wang H Z, Lu Q M, Ye C F, Liu W M, Cui Z J. Friction and wear behaviors of ionic liquid of alkylimidazolium hexafluorophosphates as lubricants for steel/steel contact. Wear256: 44–48 (2004)
Cai M R, Liang Y M, Zhou F, Liu W M. Tribological properties of novel imidazolium ionic liquids bearing benzotriazole group as the antiwear/anticorrosion additive in poly(ethylene glycol) and polyurea grease for steel/steel contacts. ACS Appl Mater Interfaces3: 4580–4592 (2011)
Qu J, Bansal D G, Yu B, Howe J Y, Luo H M, Dai S, Li H Q, Blau J, Bunting B G, Mordukhovich G, Smolenski D J. Antiwear performance and mechanism of an oil-miscible ionic liquid as a lubricant additive. ACS Appl Mater Interfaces4: 997–1002 (2012)
Phillips B S, Zabinski J S. Ionic liquid lubrication effects on ceramics in a water environment. Tribol Lett17: 533 (2004)
Palacio M, Bhushan B. Ultrathin wear-resistant ionic liquid films for novel MEMS/NEMS applications. Adv Mater20: 1194–1198 (2008)
Wang B G, Wang X B, Lou W J, Hao J C. Rheological and tribological properties of ionic liquid-based nanofluids containing functionalized multi-walled carbon nanotubes. J Phys Chem C114: 8749–8754 (2010)
Pei X W, Xia Y Q, Liu W M, Yu B, Hao J C. Polyelectrolytegrafted carbon nanotubes: Synthesis, reversible phase-transition behavior, and tribological properties as lubricant additives. J Polym Sci, Part A, Polym Chem46(21): 7225 (2008)
Lee H, Dellatore S M, Miller W M, Messersmith P B. Mussel-inspired surface chemistry for multifunctional coatings. Science318: 426–430 (2007)
Ryu J, Ku S H, Lee H, Park C B. Mussel-inspired polydopamine coating as a universal route to hydroxyapatite crystallization. Adv Funct Mater20: 2132–2139 (2010)
Kang S M, You I, Cho W K, Shon H K, Lee T G, Choi I S, Karp J M, Lee H. One-step modification of superhydrophobic surfaces by a mussel-inspired polymer coating. Angew Chem Int Ed49: 9401–9404 (2010)
Xu Y F, Peng Y B, Dearn K D, Zheng X J, Yao L L, Hu X G. Synergistic lubricating behaviors of graphene and MoS2 dispersed in esterified bio-oil for steel/steel contact. Wear342–343: 297–309 (2015)
Kalin M, Kogovšek J, Remškar M. Mechanisms and improvements in the friction and wear behavior using MoS2 nanotubes as potential oil additives. Wear280–281: 36–45 (2012)
Chen Z, Liu X W, Liu Y H, Gunsel S, Luo J B. Ultrathin MoS2 nanosheets with superior extreme pressure property as boundary lubricants. Sci Rep5: 12869 (2015)
Rabaso P, Ville F, Dassenoy F, Diaby M, Afanasiev P, Cavoret J, Vacher B, Mogne T L. Boundary lubrication: influence of the size and structure of inorganic fullerene-like MoS2 nanoparticles on friction and wear reduction. Wear320: 161–178 (2014)
Wu X H, Gong K L, Zhao G Q, Lou W J, Wang X B, Liu W M. MoS2/WS2 quantum dots as high-performance lubricant additive in polyalkylene glycol for steel/steel contact at elevated temperature. Adv Mater Interfaces5: 1700859 (2017)
Xu S J, Li D, Wu P Y. One-pot, facile, and versatile synthesis of monolayer MoS2/WS2 quantum dots as bioimaging probes and efficient electrocatalysts for hydrogen evolution reaction. Adv Funct Mater25: 1127–1136 (2015)
Matte H S S R, Gomathi A, Manna A K, Late D J, Datta R, Pati S K, Rao C N R. MoS2 and WS2 analogues of graphene. Angew Chem Int Ed49: 4059 (2010)
Chikan V, Kelley D F. Preparation of nanocrystalline ceria particles by sonochemical and microwave assisted heating methods. J Phys Chem B106: 3794 (2002)
Xu Z, Lou W J, Wu X H, Wang X B, Hao J Y. Investigating the tribological behavior of PEGylated MoS2 nanocomposites as additives in polyalkylene glycol at elevated temperature. RSC Adv7: 53346 (2017)
Rudnick L R. Lubricant Additives: Chemistry and Applications, Second Edition. Boca Raton: CRC Press, 2009.
NIST X-ray Photoelectron Spectroscopy Database, version 4.1; National Institute of Standards and Technology, Gaithersburg, MD, 2012, http://srdata.nist.gov/xps/ (accessed: March 2013).
Acknowledgements
The authors are thankful for financial support of this work by National Key Research and Development Program of China (No. 2018YFB0703802) and National Natural Science Foundation of China (Nos. NSFC51875553 and 51775536).
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Kuiliang GONG. He got his master degree (2010) in materials sicence from Qingdao University in China. He is currently a PhD candidate at Lanzhou Institute of Chemical Physics. His research is focused on nanoadditives for lubricating oil.
Xinhu WU. He got his PhD degree in 2018 at the Lanzhou Institute of Chemical Physics. He is an assistant at the State Key Lab of Solid Lubrication in Lanzhou Institute of Chemical Physics, CAS. His research interests are high-temperature lubricating oil and additives.
Xiaobo WANG. He is a full professor in Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences (CAS). He received his PhD degree in physical chemistry from LICP in 2004. His research interests include lubricating oils and greases, nano-additives, tribochemical and tribophysical. He has published more than 150 peer reviewed journal papers and authorized 19 patents.
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Gong, K., Lou, W., Zhao, G. et al. Investigation on tribological behaviors of MoS2 and WS2 quantum dots as lubricant additives in ionic liquids under severe conditions. Friction 8, 674–683 (2020). https://doi.org/10.1007/s40544-019-0290-6
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DOI: https://doi.org/10.1007/s40544-019-0290-6