Abstract
High-performance organic friction modifiers (OFMs) added to lubricating oils are crucial for reducing energy loss and carbon footprint. To establish a new class of OFMs, we measured the friction and wear properties of N-(2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl)dodecaneamide referred to as C12Amide-TEMPO. The effect of its head group chemistry, which is characterized by a rigid six-membered ring sandwiched by an amide group and a terminal free oxygen radical, was also investigated with both experiments and quantum mechanical (QM) calculations. The measurement results show that C12Amide-TEMPO outperforms the conventional OFMs of glyceryl monooleate (GMO) and stearic acid, particularly for load-carrying capacity, wear reduction, and stability of friction over time. The friction and wear reduction effect of C12Amide-TEMPO is also greatly superior to those of C12Ester-TEMPO and C12Amino-TEMPO, in which ester and amino groups replace the amide group, highlighting the critical role of the amide group. The QM calculation results suggest that, in contrast to C12Ester-TEMPO, C12Amino-TEMPO, and the conventional OFMs of GMO and stearic acid, C12Amide-TEMPO can form effective boundary films on iron oxide surfaces with a unique double-layer structure: a strong surface adsorption layer owing to the chemical interactions of the amide oxygen and free radical with iron oxide surfaces, and an upper layer owing to the interlayer hydrogen-bonding between the amide hydrogen and free radical or between the amide hydrogen and oxygen. Moreover, the intralayer hydrogen-bonding in each of the two layers is also possible. We suggest that in addition to strong surface adsorption, the interlayer and intralayer hydrogen-bonding also increases the strength of the boundary films by enhancing the cohesion strength, thereby resulting in the high tribological performance of C12Amide-TEMPO. The findings in this study are expected to provide new hints for the optimal molecular design of OFMs.
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References
Holmberg K, Erdemir A. Influence of tribology on global energy consumption, costs and emissions. Friction 5(3): 263–284 (2017)
Spikes H. Friction modifier additives. Tribol Lett 60(1): 5 (2015)
Tang Z L, Li S H. A review of recent developments of friction modifiers for liquid lubricants (2007-present). Curr Opin Solid State Mater Sci 18(3): 119–139 (2014)
Vaitkunaite G, Espejo C, Wang C, Thiébaut B, Charrin C, Neville A, Morina A. MoS2 tribofilm distribution from low viscosity lubricants and its effect on friction. Tribol Int 151: 106531 (2020)
McQueen J S, Gao H, Black E D, Gangopadhyay A K, Jensen R K. Friction and wear of tribofilms formed by zinc dialkyl dithiophosphate antiwear additive in low viscosity engine oils. Tribol Int 38(3): 289–297 (2005)
Meng Y G, Xu J, Jin Z M, Prakash B, Hu Y Z. A review of recent advances in tribology. Friction 8(2): 221–300 (2020)
Zhou Y, Qu J. Ionic liquids as lubricant additives: A review. ACS Appl Mater Interfaces 9(4): 3209–3222 (2017)
Kenbeek D, Buenemann T, Rieffe H. Review of organic friction modifiers—Contribution to fuel efficiency? SAE Technical Paper, 2000: 2000-01-1792.
Qiu S Q, Dong J X, Cheng G X. A review of ultrafine particles as antiwear additives and friction modifiers in lubricating oils. Lubr Sci 11(3): 217–226 (1999)
De Barros Bouchet M I, Martin J M, Avila J, Kano M, Yoshida K, Tsuruda T, Bai S D, Higuchi Y, Ozawa N, Kubo M, et al. Diamond-like carbon coating under oleic acid lubrication: Evidence for graphene oxide formation in superlow friction. Sci Reports 7: 46394 (2017)
Ewen J P, Gattinoni C, Morgan N, Spikes H A, Dini D. Nonequilibrium molecular dynamics simulations of organic friction modifiers adsorbed on iron oxide surfaces. Langmuir 32(18): 4450–4463 (2016)
Li W M, Kumara C, Meyer H M III, Luo H M, Qu J. Compatibility between various ionic liquids and an organic friction modifier as lubricant additives. Langmuir 34(36): 10711–10720 (2018)
Cyriac F, Yamashita N, Hirayama T, Yi T X, Poornachary S K, Chow P S. Mechanistic insights into the effect of structural factors on film formation and tribological performance of organic friction modifiers. Tribol Int 164: 107243 (2021)
Hirayama T, Kawamura R, Fujino K, Matsuoka T, Komiya H, Onishi H. Cross-sectional imaging of boundary lubrication layer formed by fatty acid by means of frequency-modulation atomic force microscopy. Langmuir 33(40): 10492–10500 (2017)
Wells H M, Southcombe J E. The theory and practice of lubrication: The ‘“Germ”’ process. J Soc Chem Ind 39(5): T51–T66 (1920)
Deeley R M. Discussion on lubrication. Proc Phys Soc London 32(1): 1s (1919)
Guegan J, Southby M, Spikes H. Friction modifier additives, synergies and antagonisms. Tribol Lett 67(3): 83 (2019)
Ratoi M, Niste V B, Alghawel H, Suen Y F, Nelson K. The impact of organic friction modifiers on engine oil tribofilms. RSC Adv 4(9): 4278–4285 (2014)
Schwartz D K. Mechanisms and kinetics of self-assembled monolayer formation. Annu Rev Phys Chem 52: 107–137 (2001)
Beltzer M, Jahanmir S. Role of dispersion interactions between hydrocarbon chains in boundary lubrication. A S L E Trans 30(1): 47–54 (1987)
Jahanmir S. Chain length effects in boundary lubrication. Wear 102(4): 331–349 (1985)
Jahanmir S, Beltzer M. Effect of additive molecular structure on friction coefficient and adsorption. J Tribol 108(1): 109–116 (1986)
Okabe H, Masuko M, Sakurai K. Dynamic behavior of surface-adsorbed molecules under boundary lubrication. A S L E Trans 24(4): 467–473 (1981)
Campen S M. Fundamentals of organic friction modifier behaviour. Ph.D. Thesis. London (UK): Imperial College London, 2012.
Zhang X W, Tsukamoto M, Zhang H D, Mitsuya Y, Itoh S, Fukuzawa K. Experimental study of application of molecules with a cyclic head group containing a free radical as organic friction modifiers. J Adv Mech Des Syst Manuf 14(4): JAMDSM0044 (2020)
Onumata Y, Zhao H Y, Wang C, Morina A, Neville A. Interactive effect between organic friction modifiers and additives on friction at metal pushing V-belt CVT components. Tribol Trans 61(3): 474–481 (2018)
Cyriac F, Tee X Y, Poornachary S K, Chow P S. Influence of structural factors on the tribological performance of organic friction modifiers. Friction 9(2): 380–400 (2021)
Fry B M, Moody G, Spikes H A, Wong J S S. Adsorption of organic friction modifier additives. Langmuir 36(5): 1147–1155 (2020)
Fry B M, Chui M Y, Moody G, Wong J S S. Interactions between organic friction modifier additives. Tribol Int 151: 106438 (2020)
Kano M, Yasuda Y, Okamoto Y, Mabuchi Y, Hamada T, Ueno T, Ye J, Konishi S, Takeshima S, Martin J M, et al. Ultralow friction of DLC in presence of glycerol mono-oleate (GNO). Tribol Lett 18(2): 245–251 (2005)
Kuwahara T, Romero P A, Makowski S, Weihnacht V, Moras G, Moseler M. Mechano-chemical decomposition of organic friction modifiers with multiple reactive centres induces superlubricity of ta-C. Nat Commun 10: 151 (2019)
Tatsumi G, Ratoi M, Shitara Y, Sakamoto K, Mellor B G. Effect of organic friction modifiers on lubrication of PEEK-steel contact. Tribol Int 151: 106513 (2020)
Nalam P C, Pham A, Castillo R V, Espinosa-Marzal R M. Adsorption behavior and nanotribology of amine-based friction modifiers on steel surfaces. J Phys Chem C 123(22): 13672–13680 (2019)
Hu W J, Xu Y H, Zeng X Q, Li J S. Alkyl-ethylene amines as effective organic friction modifiers for the boundary lubrication regime. Langmuir 36(24): 6716–6727 (2020)
Pominov A, Müller-Hillebrand J, Träg J, Zahn D. Interaction models and molecular simulation systems of steel-organic friction modifier interfaces. Tribol Lett 69(1): 14 (2021)
Desanker M, He X L, Lu J, Liu P Z, Pickens D B, Delferro M, Marks T J, Chung Y W, Wang Q J. Alkyl-cyclens as effective sulfur- and phosphorus-free friction modifiers for boundary lubrication. ACS Appl Mater Interfaces 9(10): 9118–9125 (2017)
Desanker M, He X L, Lu J, Johnson B A, Liu Z, Delferro M, Ren N, Lockwood F E, Greco A, Erdemir A, et al. High-performance heterocyclic friction modifiers for boundary lubrication. Tribol Lett 66(1): 50 (2018)
He X L, Lu J, Desanker M, Invergo A M, Lohr T L, Ren N, Lockwood F E, Marks T J, Chung Y W, Wang Q J. Boundary lubrication mechanisms for high-performance friction modifiers. ACS Appl Mater Interfaces 10(46): 40203–40211 (2018)
Cosimbescu L, Demas N G, Robinson J W, Erck R A. Friction- and wear-reducing properties of multifunctional small molecules. ACS Appl Mater Interfaces 10(1): 1317–1323 (2018)
Jaishankar A, Jusufi A, Vreeland J L, Deighton S, Pellettiere J, Schilowitz A M. Adsorption of stearic acid at the iron oxide/oil interface: Theory, experiments, and modeling. Langmuir 35(6): 2033–2046 (2019)
Li D M, Gao P, Sun X J, Zhang S W, Zhou F, Liu W M. The study of TEMPOs as additives in different lubrication oils for steel/steel contacts. Tribol Int 73: 83–87 (2014)
Prutton C F, Frey D R, Turnbull D, Dlouhy G. Corrosion of metals by organic acids in hydrocarbon solvents. Ind Eng Chem 37(1): 90–100 (1945)
Gallez B, Demeure R, Debuyst R, Leonard D, Dejehet F, Dumont P. Evaluation of nonionic nitroxyl lipids as potential organ-specific contrast agents for magnetic resonance imaging. Magn Reson Imaging 10(3): 445–455 (1992)
Nakatsuji S, Mizumoto M, Ikemoto H, Akutsu H, Yamada J I. Preparation and properties of organic radical compounds with mesogenic cores. Eur J Org Chem 2002(12): 1912–1918 (2002)
Waggoner A S, Keith A D, Griffith O H. Electron spin resonance of solubilized long-chain nitroxides. J Phys Chem 72(12): 4129–4132 (1968)
Li X, Deng X R, Kousaka H, Umehara N. Comparative study on effects of load and sliding distance on amorphous hydrogenated carbon (a-C:H) coating and tetrahedral amorphous carbon (ta-C) coating under base-oil lubrication condition. Wear 392-393: 84–92 (2017)
Liu X X, Yamaguchi R, Umehara N, Deng X R, Kousaka H, Murashima M. Clarification of high wear resistance mechanism of ta-CNx coating under poly alpha-olefin (PAO) lubrication. Tribol Int 105: 193–200 (2017)
Frisch M J, Trucks G W, Schlegel H B, Scuseria G E, Robb M A, Cheeseman J R, et al. Gaussian 16, revision C.01. Wallingford CT (USA): Gaussian, Inc., 2016.
Zhao Y, Truhlar D G. The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements: Two new functionals and systematic testing of four M06-class functionals and 12 other functionals. Theor Chem Acc 120: 215–241 (2008)
Ditchfield R, Hehre W J, Pople J A. Self-consistent molecular-orbital methods. IX. An extended Gaussian-type basis for molecular-orbital studies of organic molecules. J Chem Phys 54(2): 724–728 (1971)
Hariharan P C, Pople J A. The influence of polarization functions on molecular orbital hydrogenation energies. Theor Chimica Acta 28(3): 213–222 (1973)
Hehre W J, Ditchfield R, Pople J A. Self-consistent molecular orbital methods. XII. Further extensions of Gaussian-type basis sets for use in molecular orbital studies of organic molecules. J Chem Phys 56(5): 2257–2261 (1972)
Gattinoni C, Ewen J P, Dini D. Adsorption of surfactants on α-Fe2O3(0001): A density functional theory study. J Phys Chem C 122(36): 20817–20826 (2018)
Finger L W, Hazen R M. Crystal structure and isothermal compression of Fe2O3, Cr2O3, and V2O3 to 50 kbars. J Appl Phys 51(10): 5362–5367 (1980)
Dudarev S L, Botton G A, Savrasov S Y, Humphreys C J, Sutton A P. Electron-energy-loss spectra and the structural stability of nickel oxide: An LSDA+U study. Phys Rev B 57(3): 1505–1509 (1998)
Al-Kuhaili M F, Saleem M, Durrani S M A. Optical properties of iron oxide (α-Fe2O3) thin films deposited by the reactive evaporation of iron. J Alloys Compd 521: 178–182 (2012)
Klimeš J, Bowler D R, Michaelides A. Van der Waals density functionals applied to solids. Phys Rev B 83(19): 195131 (2011)
Fry B M, Moody G, Spikes H, Wong J S S. Effect of surface cleaning on performance of organic friction modifiers. Tribol Trans 63(2): 305–313 (2020)
Lu T, Chen F W. Multiwfn: A multifunctional wavefunction analyzer. J Comput Chem 33(5): 580–592 (2012)
Lu T, Chen F W. Quantitative analysis of molecular surface based on improved Marching Tetrahedra algorithm. J Mol Graph Model 38: 314–323 (2012)
Humphrey W, Dalke A, Schulten K. VMD: Visual molecular dynamics. J Mol Graph 14(1): 33–38 (1996)
Maslen E N, Streltsov V A, Streltsova N R, Ishizawa N. Synchrotron X-ray study of the electron density in α-Fe2O3. Acta Crystallogr Sect B 50(4): 435–441 (1994)
Momma K, Izumi F. VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data. J Appl Crystallogr 44(6): 1272–1276 (2011)
Minami I, Mori S. Concept of molecular design towards additive technology for advanced lubricants. Lubr Sci 19(2): 127–149 (2007)
Acknowledgements
This work was supported in part by JSPS KAKENHI Grant (Nos. 19K21915 and 21H01238), JST Adaptable and Seamless Technology Transfer Program through Target-driven R&D (No. JPMJTM19FN), and NSK Foundation for Mechatronics Technology Advancement. We thank Dr. Kin-ichi OYAMA (Research Center for Materials Science, Nagoya University) for mass spectrometry analysis of the synthesized OFMs and associate professor Takayuki TOKOROYAMA (Graduate School of Engineering, Nagoya University) for the help with wear scar measurements. Jinchi HOU is grateful for the financial support from the China Scholarship Council (No. 202006030017).
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Jinchi Hou. He received his M.S. degree in power engineering and engineering thermophysics in 2020 from Beijing Institute of Technology, Beijng, China. He is currently a Ph.D. student at the Graduate School of Informatics, Nagoya University, Japan. His research interests focus on the applications of organic friction modifiers in nano-lubrication.
Masaki Tsukamoto. He received his M.S. and Ph.D. degrees in chemistry from Nagoya University, Japna, in 1994 and 1999, respectively. After working as a postdoctoral fellow at Université Paris-Sud, France, he joined the Graduate School of Information Science, Nagoya University from 2003. His current position is the lecturer at the Graduate School of Informatics, Nagoya University. His research interests include chemical synthesis of biologically relevant compounds, polymers, and organic friction modifiers.
Seanghai Hor. He received his M.S. degree in chemistry from Royal University of Phnom Penh, Cambodia, in 2015. He was an M.Ed. student at Aichi University of Education, Japan, from 2017 to 2019. He has recently earned his Ph.D. degree in informatics at Nagoya University, Japan. His current position is a teacher trainer at National Institute of Education, Cambodia. His research interests cover the organic and polymer synthesis.
Xingyu Chen. He received his M.S. degree in vehicle operation engineering in 2019 from Beijing Jiaotong University, Beijing, China. He is currently a Ph.D. student at the Graduate School of Informatics, Nagoya University, Japan. His research interests focus on molecular orientation and chemical reaction in nano-lubrication, and multiscale computational simulations.
Juntao Yang. He received his B.E. degree in mechanical design and manufacturing and its automation from Guangdong University of Technology, China, in 2018. Then he pursed graduate studies at Nagoya University, Japan and received his M.S. degree in informatics in 2022. His research interests include molecular simulation, quantum mechanics calculation, machine learning, and tribological phenomena.
Hedong Zhang. She received her B.E. degree in optical technique and photo-electric instrumentation from Zhejiang University, China, in 1994, and Ph.D. degree in electronic-mechanical engineering from Nagoya University, Japan, in 2002. Since then, she has been a member of the faculty at Nagoya University. She is currently a professor at the Graduate School of Informatics, Nagoya University. Her research interests include molecular simulation techniques, material informatics, and measurement techniques at the nanoscale, particularly for applications in the field of tribology.
Nobuaki Koga. He received his Ph.D. degree in engineering from Kyoto University, Japan, in 1987. He was a research associate at the Institute for Molecular Science from 1986 to 1993 and an associate professor at Nagoya University, Japan, from 1993 to 1998. Since 1998, he has been a professor at Nagoya University. His research interests include chemical reactivity and excited state properties of organic and organometallic compounds.
Koji Yasuda. He received his M.S. and Ph.D. degrees in engineering from Kyoto University, Japan, in 1994 and 1997 respectively. He joined the Graduate School of Information Science at Nagoya University, Japan, from 1997. His current position is an associate professor. His research areas cover the quantum chemistry, solid state physics, and cheminformatics.
Kenji Fukuzawa. He received M. Eng. in 1987 and Dr. Eng. in applied physics in 1997 from Nagoya University, Japan. He joined Nippon Telegraph and Telephone Corporation, Japan, in 1987 and was employed as a senior research engineer until 2000. He is currently a professor of the Department of Micro-Nano Mechanical Science and Engineering, Nagoya University. His research interests are micro/nano mechanical device engineering, nano-tribology, and their related measurement science and technology.
Shintaro Itoh. He received his Ph.D. degree in electromechanical engineering from Nagoya University, Japan, in 2006. Presently he is an associate professor at the Department of Micro-Nano Mechanical Science and Engineering, Nagoya University. His research areas are nano-metrology, nano-tribology, nano-rheology, and nano-fluidics. Especially his research interests include various kinds of solid-liquid interfacial phenomena ranging from confined liquid between solid surfaces to molecularly thin liquid films on solid surfaces.
Naoki Azuma. He received his M.S. and Ph.D. degrees in mechanical engineering from Nagoya University, Japan, in 2016 and 2018 respectively. His current position is an assistant professor at the department of Micro-Nano Mechanical Science and Engineering, Nagoya University. His research interests include micro-nano metrology, bioanalysis, micro-fluidic device, and micro-nano tribology.
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Hou, J., Tsukamoto, M., Hor, S. et al. Molecules with a TEMPO-based head group as high-performance organic friction modifiers. Friction 11, 316–332 (2023). https://doi.org/10.1007/s40544-022-0610-0
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DOI: https://doi.org/10.1007/s40544-022-0610-0