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Song W, Campen S, Shiel H, Gattinoni C, Zhang J, Wong JSS. Position of Carbonyl Group Affects Tribological Performance of Ester Friction Modifiers. ACS APPLIED MATERIALS & INTERFACES 2024; 16:14252-14262. [PMID: 38456401 PMCID: PMC10958443 DOI: 10.1021/acsami.3c16432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/16/2024] [Accepted: 02/23/2024] [Indexed: 03/09/2024]
Abstract
The tribological properties of lubricants can be effectively improved by the introduction of amphiphilic molecules, whose performance is largely affected by their polar head groups. In this work, the tribological performance in steel-steel contacts of two isomers, glycerol monostearate (GMS) and stearyl glycerate (SG), a glyceride and a glycerate, were investigated as organic friction modifiers (OFM) in hexadecane. SG exhibits a much lower friction coefficient and wear than GMS despite their similar structures. The same applies when comparing the performance of oleyl glycerate (OG) and its isomer, glycerol monooleate (GMO). Surface chemical analysis shows that SG forms a polar, carbon-based, tribofilm of around tens of nanometers thick, while GMS does not. This tribofilm shows low friction and robustness under nanotribology test, which may contribute to its superior performance at the macro-scale. The reason for this tribofilm formation can be due to the stronger adsorption of SG on the steel surface than that of GMS. The tribofilm formation can be stress-activated since lower friction and higher tribofilm coverage can be obtained under high load. This work offers insights into the lubrication mechanism of a novel OFM and provides strategies for OFM design.
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Affiliation(s)
- Wei Song
- The
Tribology Group, Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ, U.K.
| | - Sophie Campen
- The
Tribology Group, Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ, U.K.
| | - Huw Shiel
- Department
of Material, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ, U.K.
| | - Chiara Gattinoni
- Department
of Physics, King’s College London, Strand, London WC2R 2LS, U.K.
| | - Jie Zhang
- The
Tribology Group, Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ, U.K.
| | - Janet S. S. Wong
- The
Tribology Group, Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ, U.K.
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2
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Huang G, Sun L, Li L, Pei L, Xue W, Wang R, Wang Y. Exploring the Effect Mechanism of Alkyl Chain Lengths on the Tribological Performance of Ionic Liquids. ACS OMEGA 2024; 9:3184-3192. [PMID: 38284007 PMCID: PMC10809665 DOI: 10.1021/acsomega.3c01885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 06/13/2023] [Indexed: 01/30/2024]
Abstract
In this work, four kinds of imidazole phosphate ionic liquids (ILs) with different anionic and cationic alkyl chain lengths were synthesized. The physicochemical properties and tribological performance of ILs were evaluated. The experimental results revealed that the tribological properties of ILs were positively correlated with the cationic chain length and negatively correlated with the anionic chain length. The effect mechanism can be summarized in two aspects: on the one hand, anions with shorter alkyl chain lengths possess stronger adsorption performance and better film forming ability on the friction pair surfaces, which makes the ILs form more robust and stable lubricating film; on the other hand, ILs with longer cationic alkyl chain lengths possess milder tribo-chemical reactions, which can effectively enhance the tribological performance and decrease the corrosion wear.
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Affiliation(s)
- Guowei Huang
- State
Key Laboratory of Advanced Processing and Recycling of Nonferrous
Metals, Lanzhou University of Technology, 730050 Lanzhou, Gansu, P. R. China
| | - Li Sun
- State
Key Laboratory of Advanced Processing and Recycling of Nonferrous
Metals, Lanzhou University of Technology, 730050 Lanzhou, Gansu, P. R. China
| | - Luxing Li
- State
Key Laboratory of Advanced Processing and Recycling of Nonferrous
Metals, Lanzhou University of Technology, 730050 Lanzhou, Gansu, P. R. China
| | - Linlu Pei
- State
Key Laboratory of Advanced Processing and Recycling of Nonferrous
Metals, Lanzhou University of Technology, 730050 Lanzhou, Gansu, P. R. China
| | - Wangle Xue
- State
Key Laboratory of Advanced Processing and Recycling of Nonferrous
Metals, Lanzhou University of Technology, 730050 Lanzhou, Gansu, P. R. China
| | - Ruichao Wang
- State
Key Laboratory of Advanced Processing and Recycling of Nonferrous
Metals, Lanzhou University of Technology, 730050 Lanzhou, Gansu, P. R. China
| | - Yifei Wang
- Dulwich
International High School Zhuhai, 519060 Zhuhai, Guangdong, P. R. China
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3
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Shi Y, Yang S, Zhang X, Liu W. Towards outstanding lubricity performance of proton-type ionic liquids or synergistic effects with friction modifiers used as oil additives at the steel/steel interface. SOFT MATTER 2024; 20:365-374. [PMID: 38093713 DOI: 10.1039/d3sm01250f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Anti-wear (AW) additives and friction modifiers (FMs) and their interactions in lubricants are critical to tribological performance. This research investigates the compatibility and synergism of three oil-soluble alkylamine-phosphate ionic liquids with friction modifiers, organomolybdenum compounds. Three proton-based ionic liquids (PILs) were synthesized using a simple, low-cost, and unadulterated procedure as well as the chain lengths of the PILs affected the effectiveness of friction reduction and anti-wear. For example, the effect of a short-chain PIL alone as an additive on friction and wear behavior was not significant, whereas a long-chain PIL was more effective. In addition, PILs appeared to be able to coexist with organic molybdenum compounds and worked synergistically with dialkyl dithiophosphate oxygen molybdenum (MoDDP) to produce a sustained low coefficient of boundary friction (the coefficient of friction approaching 0.042). We proposed a three-stage tribochemical process to explain this interaction of PILs + MoDDP with contact surfaces to form physically adsorbed friction-reducing films and chemically reactive wear-protective films. This study reveals the compatibility and synergistic effects of two common lubricant components, which can be used to guide lubricant development in the future.
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Affiliation(s)
- Yongjia Shi
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
| | - Shenghui Yang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
| | - Xia Zhang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
- Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai, No. 300, Changjiang Road, Yantai, Shandong 264006, China
- Qingdao Key Laboratory of Lubrication Technology for Advanced Equipment, Qingdao Center of Resource Chemistry & New Materials, Qingdao 266000, China
| | - Weimin Liu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
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4
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Kerr A, Häkkinen S, Hall SCL, Kirkman P, O’Hora P, Smith T, Kinane CJ, Caruana A, Perrier S. Anchor Group Bottlebrush Polymers as Oil Additive Friction Modifiers. ACS APPLIED MATERIALS & INTERFACES 2023; 15:48574-48583. [PMID: 37811661 PMCID: PMC10591277 DOI: 10.1021/acsami.3c12628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 09/21/2023] [Indexed: 10/10/2023]
Abstract
Surface-tethered polymers have been shown to be an efficient lubrication strategy for boundary and mixed lubrication by providing a solvated film between solid surfaces. We have assessed the performance of various graft copolymers as friction modifier additives in oil and revealed important structure-property relationships for this application. The polymers consisted of an oil-soluble, grafted poly(lauryl acrylate) segment and a polar, linear poly(4-acryloylmorpholine) anchor group. Reversible addition-fragmentation chain transfer polymerization was used to access various architectures with control of the grafting density and position of the anchor group. Macrotribological studies displayed promising results with ≈50% reduction in friction coefficient at low polymer treatment rates. QCM-D experiments, neutron reflectometry, small-angle neutron scattering, and atomic force microscopy were used to gather detailed information on these polymers' surface adsorption characteristics, film structure, and solution behavior.
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Affiliation(s)
- Andrew Kerr
- Department
of Chemistry, The University of Warwick, Coventry CV4 7AL, U.K.
| | - Satu Häkkinen
- Department
of Chemistry, The University of Warwick, Coventry CV4 7AL, U.K.
| | - Stephen C. L. Hall
- Department
of Chemistry, The University of Warwick, Coventry CV4 7AL, U.K.
| | - Paul Kirkman
- Lubrizol
Limited, The Knowle, Nether Lane, Hazelwood DE56 4AN, Derbyshire, U.K.
| | - Paul O’Hora
- Lubrizol
Limited, The Knowle, Nether Lane, Hazelwood DE56 4AN, Derbyshire, U.K.
| | - Timothy Smith
- Lubrizol
Limited, The Knowle, Nether Lane, Hazelwood DE56 4AN, Derbyshire, U.K.
| | - Christian J. Kinane
- Rutherford
Appleton Laboratory, ISIS Neutron and Muon
Sourcey, Didcot OX11 0QX, U.K.
| | - Andrew Caruana
- Rutherford
Appleton Laboratory, ISIS Neutron and Muon
Sourcey, Didcot OX11 0QX, U.K.
| | - Sébastien Perrier
- Department
of Chemistry, The University of Warwick, Coventry CV4 7AL, U.K.
- Warwick
Medical School, The University of Warwick, Coventry CV4 7AL, U.K.
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5
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Chen X, Yang J, Yasuda K, Koga N, Zhang H. Adsorption Behavior of TEMPO-Based Organic Friction Modifiers during Sliding between Iron Oxide Surfaces: A Molecular Dynamics Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3170-3179. [PMID: 35235329 DOI: 10.1021/acs.langmuir.1c03203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Organic friction modifiers (OFMs) added to lubricating oils to reduce friction and wear are crucial for reducing energy loss and CO2 emissions. In our previous studies, we have developed N-(2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl)dodecaneamide, referred to as C12TEMPO, as a new type of OFM and experimentally demonstrated its superior performance to conventional OFMs of stearic acid and glycerol monooleate. However, the behavior of C12TEMPO adsorbing onto solid surfaces from base oil during sliding, which largely dictates the lubrication performance, is yet to be elucidated. Here, we performed molecular dynamics simulations for confined shear of a C12TEMPO solution in poly-α-olefin between hematite surfaces. Unlike conventional OFMs, which typically have one functional group or multiple functional groups of the same type, C12TEMPO features two functional groups of different types: one amide and one terminal free oxygen radical. The results showed that adsorbed boundary films with a double-layer structure form stably during sliding, owing to double- or single-site surface adsorption and interlayer hydrogen bonding via the two functional groups. Additionally, some molecules in each of the first and second layers also form intralayer hydrogen bonding. Such multitype adsorption is unique and favorable for enhancing the strength of boundary films to withstand heavily loaded and prolonged sliding. The velocity distribution indicates that the first and second layers are solid- and liquid-like, respectively. The second layer could act as a buffer for the first layer, which is the last barrier to prevent solid-solid contact, against shear. We also found that the second layer can act as a reservoir to rapidly repair the once depleted region in the first layer because of the interlayer hydrogen bonding. The combination of the high strength and self-repair ability of the C12TEMPO boundary films can rationally explain the experimentally observed properties of high load-carrying capacity, excellent antiwear effect, and high stability of friction over time.
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Affiliation(s)
- Xingyu Chen
- Department of Complex Systems Science, Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Juntao Yang
- Department of Complex Systems Science, Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Koji Yasuda
- Institute of Materials and Systems for Sustainability, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Nobuaki Koga
- Department of Complex Systems Science, Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hedong Zhang
- Department of Complex Systems Science, Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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6
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Hu W, Li J. Synthesis of Bis/triaza Crown Ethers and Study of Their Properties as Friction Modifiers ※. ACTA CHIMICA SINICA 2022. [DOI: 10.6023/a21120570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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7
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Srivastava I, Kotia A, Ghosh SK, Ali MKA. Recent advances of molecular dynamics simulations in nanotribology. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116154] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Lubrication and Anti-Rust Properties of Jeffamine-Triazole Derivative as Water-Based Lubricant Additive. COATINGS 2021. [DOI: 10.3390/coatings11060679] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
With the worldwide concern of environmental protection, water-based lubricants exhibit extensive potential applications due to their advantages of energy-conservation, innocuity, and competitive price. Nonetheless, the common lubricating additives currently available in the market are mainly oil-based, while multifunctional water lubricants are rare. This paper reports a sulfur- and phosphorus-free multifunctional additive with high water-solubility, which is applicable for multitype material surfaces. Specifically, through the Mannich reaction method, a Jeffamine-triazole derivative was synthesized from olyetheramine and benzotriazole. Compared with distilled water, the derivative exhibited superior friction reduction and wear resistance properties in water, with the friction reduction rate up to 72.7% and 70.2% for steel/steel and steel/aluminum contacts, respectively, when the concentration of the JD2000 is 2 wt.%. Remarkably, the wear resistance property for steel/aluminum contact is improved by 88.2%. Moreover, the additive showed corrosion inhibition on the metal surface by 75.5%. We further revealed the lubrication and anti-rust mechanisms: the additives are adsorbed on the surfaces through nitrogen atoms, and the long-chain structure of polyether can cover the sliding surfaces, forming a stable viscoelastic film to prevent the severe damages caused by the direct contact between rough friction pairs. Concurrently, the dense protective film can resist the corrosion of environmental media on the metal surface and delay the metal rust. This research may provide a candidate for an ecofriendly multifunctional water-based lubricating additive.
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9
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Yang M, Fan S, Huang H, Zhang Y, Huang Z, Hu H, Liang J. In-situ synthesis of calcium borate/cellulose acetate-laurate nanocomposite as efficient extreme pressure and anti-wear lubricant additives. Int J Biol Macromol 2020; 156:280-288. [DOI: 10.1016/j.ijbiomac.2020.04.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/19/2020] [Accepted: 04/04/2020] [Indexed: 11/28/2022]
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10
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Shi J, Zhou Q, Sun K, Liu G, Zhou F. Understanding Adsorption Behaviors of Organic Friction Modifiers on Hydroxylated SiO 2 (001) Surfaces: Effects of Molecular Polarity and Temperature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8543-8553. [PMID: 32610909 DOI: 10.1021/acs.langmuir.0c01386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Molecular dynamics simulations are used to investigate the physisorption of organic friction modifiers (OFMs) lubricated by 1-decene trimer (PAO4) representing a base oil and confined between hydroxylated SiO2 (001) surfaces. The results indicate that OFM molecules form dense, tendentiously vertical monolayer films at low temperature but loose adsorption layers at high temperature, particularly for R-NH2 with weaker molecular polarity. The structural information is quantitatively clarified by mass density profiles, radial distribution function, and probability distributions of an end-to-end distance at a perpendicular-to-surface direction. The movement performance of lubricant, reflected by the thickness of the organic part and radius of gyration of PAO4 molecules, strongly depends on temperature. The adsorption amount of OFM molecules decreases dramatically with lowering OFM polarity and increasing temperature above the critical desorption temperatures of about 320, 373, and 453 K for amine (R-NH2), alcohol (R-OH), and acid (R-COOH), respectively. The interaction energies of the OFM-surface decrease continuously for the R-NH2 system with temperature and decrease rapidly as temperature exceeds a critical value for both R-OH and R-COOH systems. The single-molecule geometry optimization validates the significant role of the electrostatic and hydrogen-bond attractions in molecular adsorption. Therefore, the OFMs with stronger polarity (like R-COOH) present stronger adsorption and better temperature resistance. The findings in this work are of particular value and provide a guideline in designing and engineering novel OFM additives for extreme lubrication conditions.
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Affiliation(s)
- Junqin Shi
- State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, Northwestern Polytechnical University, Xi'an 710072, China
| | - Qing Zhou
- State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, Northwestern Polytechnical University, Xi'an 710072, China
| | - Kun Sun
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Guoqiang Liu
- State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, Northwestern Polytechnical University, Xi'an 710072, China
| | - Feng Zhou
- State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, Northwestern Polytechnical University, Xi'an 710072, China
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
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11
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Song W, Chen P, Yan J, Zhu W, Ji H. The Tribological Properties of Reduced Graphene Oxide Doped by N and B Species with Different Configurations. ACS APPLIED MATERIALS & INTERFACES 2020; 12:29737-29746. [PMID: 32510914 DOI: 10.1021/acsami.0c03467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Reduced graphene oxide (rGO) was doped by nitrogen (N) and/or boron (B), leading to four different configurations: N-rGO (N-doped rGO), B-rGO (B-doped rGO), N-B-rGO (N and B codoped rGO with formation of B-N bond), and N,B-rGO (N and B isolate-doped rGO without formation of B-N bond). The preparations of different configurations were controlled by the chemical vapor deposition procedure, and their structures were further confirmed by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and X-ray diffraction (XRD). The tribological performance of these was tested via a ball-on-flat tribometer under 5 N load. N,B-rGO displayed better friction-reducing and antiwear performance than N-rGO and B-rGO, while N-B-rGO presented poorer tribological properties. The morphology and components of the wear track after friction were further explored, revealing that N,B-rGO can be adsorbed on the rubbing surface to form a graphene-based protective layer, while N-B-rGO cannot. In addition, first-principles calculations based on density functional theory further confirmed a stronger interfacial energy of N,B-rGO on steel surface than that of N-B-rGO on the steel surface, which was in accordance with the experimental results.
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Affiliation(s)
- Wei Song
- Fine Chemical Industry Research Institute, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
| | - Pin Chen
- National Supercomputer Center in Guangzhou, School of Data and Computer Science, Sun Yat-Sen University, Guangzhou 510006, China
| | - Jincan Yan
- Fine Chemical Industry Research Institute, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wenshuai Zhu
- School of Chemistry and Chemical Engineering, Institute for Energy Research, Jiangsu University, Zhenjiang 212013, China
| | - Hongbing Ji
- Fine Chemical Industry Research Institute, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China
- School of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China
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12
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Hu W, Xu Y, Zeng X, Li J. Alkyl-Ethylene Amines as Effective Organic Friction Modifiers for the Boundary Lubrication Regime. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6716-6727. [PMID: 32460502 DOI: 10.1021/acs.langmuir.0c00793] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
With the pursuit of fuel economy in the automotive industry, recently low-viscosity lubricant technology has been widely improved. The present work has systematically discussed a series of sulfur- and phosphorus-free organic friction modifiers (FMs)-alkyl-ethylene amines-by alkyl substitution from ethylene amines with various nitrogen-atom numbers and molecular configurations. Herein, the pin-on-flat reciprocation friction tests have exhibited that the addition of the novel alkyl-ethylene amines into base oil led to significant reductions in the friction coefficient (up to 23%). Further investigations of tribological properties at elevated temperatures demonstrated that the increased number of nitrogen atoms and the regular linear atomic arrangement contributed to an improvement of friction reduction (up to 66%) compared to the neat base oil. Notably, results of water contact angle measurement and infrared spectroscopy (IR) have provided favorable evidence that the novel FMs have adsorbed on the metal surface leading to the formation of a tribofilm, whereby the tribofilm prevented the sliding surfaces from direct asperity contact and markedly improved the tribological performance, as seen from the composition analysis of the worn surfaces by an energy-dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), and confocal Raman spectroscopy. Therefore, the present work can provide a practical reference for molecular structure design through investigation of structure-performance relations of lubricant additives.
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Affiliation(s)
- Wenjing Hu
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanhui Xu
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Xiangqiong Zeng
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Jiusheng Li
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
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13
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Ma J, Xiao Y, Sun Y, Hu J, Wang Y. Sulfur-Doped Alkylated Graphene Oxide as High-Performance Lubricant Additive. NANOSCALE RESEARCH LETTERS 2020; 15:26. [PMID: 32002704 PMCID: PMC6990272 DOI: 10.1186/s11671-020-3257-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/20/2020] [Indexed: 06/10/2023]
Abstract
Sulfur-doped graphene oxide (SA-GO) prepared by sulfuration and alkylation of graphene oxide is applied as an efficient green anti-wear additive for harsh operation conditions of engines. X-ray photoelectron spectroscopy analysis reveals the sulfur content of octadecylamine-modified SA-GO (sulfuration follows alkylation) is increased by 79 times compared with the reverse process that alkylation follows sulfuration, suggesting the preparation route is a key factor of the sulfuration process. The higher sulfur content and -C-S-C- sulfur bonding constitution result better lubrication effect, while the investigation of chain length of alkylation modification and concentration of the alkylated sulfur-doped graphene oxide indicates the octylamine-modified SA-GO shows smaller diameter of wear scar within the concentration range between 1 × 10-4 and 2.5 × 10-4 wt%. The decrement percent of wear scar diameter is 43.2% in 928 lubrication oil and 17.2% in PAO4 oil while the SA-GO modified by octylamine is applied with the concentrations 2.5 × 10-4 wt% in PAO4 and 1 × 10-4 wt% in 928 oil, respectively. The sulfur content in oil samples is only 0.006~0.001 wt%, which is much lower than the sulfur content standard recommended by ILSAC that is 0.5 wt%. The research work indicates the SA-GO additive is more feasible for the pollution treatment which focuses the substantial reduction of sulfur content in lubrication oil on the premise of improving lubrication capability.
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Affiliation(s)
- Jun Ma
- Air Force Logistics College, Xuzhou, 221000, People's Republic of China.
| | - Yunpeng Xiao
- Air Force Logistics College, Xuzhou, 221000, People's Republic of China
| | - Yuanbao Sun
- Air Force Logistics College, Xuzhou, 221000, People's Republic of China
| | - Jianqiang Hu
- Air Force Logistics College, Xuzhou, 221000, People's Republic of China
| | - Yuelun Wang
- Key Laboratory of Coal Processing and Efficient Utilization, Ministry of Education, China University of Mining & Technology, Xuzhou, 221116, People's Republic of China.
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14
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Kavita, Verma P, Verma DK, Kumar B, Singh AK, Shukla N, Srivastava V, Rastogi RB. Tetrahydropyrazolopyridines as antifriction and antiwear agents: experimental and DFT calculations. RSC Adv 2020; 10:10188-10196. [PMID: 35498590 PMCID: PMC9050401 DOI: 10.1039/d0ra00794c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 03/02/2020] [Indexed: 11/21/2022] Open
Abstract
Some tetrahydropyrazolopyridines (THPP-H) with the methoxy (THPP-OMe) and methyl (THPP-Me) substituents were synthesized by a one-pot multi-component reaction. NMR spectroscopy (1H and 13C) was used to authenticate the synthesis. According to the results of tribological tests ASTM D4172, and ASTM D5183 on a four-ball tester in paraffin oil (PO) at a concentration of 0.25% w/v, their relative tribo-activity along with a reference additive, zinc dialkyldithiophosphate (ZDDP) could be figured out as mentioned below-THPP-OMe > THPP-Me > THPP-H > ZDDP. The calculation of frictional power loss from the coefficient of friction data of the tested additives supports the given order. As is apparent from AFM and SEM micrographs of the wear scar surface for plain oil with and without different tetrahydropyrazopyridines, surface evenness endorses the above trend. Proof for strong adsorption of the synthesized additives is provided by EDX analysis of the steel ball surface after performing the tribological test, where nitrogen and oxygen are vividly seen as heteroatoms. XPS studies reveal the composition of the in situ formed tribofilm. The moieties containing carbon bonded to oxygen/nitrogen as decomposed products of the additive together with oxides of iron in +II or +III oxidation states are perceptible in the tribofilm, the tribofilm interferes with the proximity of the surfaces keeping them far apart. Consequently, friction and wear are remarkably reduced. Findings from Density Functional Theory (DFT) calculations are in full agreement with the results obtained from tribological experiments. MWD in the presence of PO and its admixture with THPP-OMe.![]()
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Affiliation(s)
- Kavita
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
| | - Pratibha Verma
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
| | - Dinesh K. Verma
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
- Department of Chemistry
| | - Bharat Kumar
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
| | - Alok K. Singh
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
| | - Nivedita Shukla
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
| | - Vandana Srivastava
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
| | - Rashmi B. Rastogi
- Department of Chemistry
- Indian Institute of Technology (Banaras Hindu University)
- Varanasi-221005
- India
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15
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Hu W, Zhang Z, Zeng X, Li J. Correlation between the Degree of Alkylation and Tribological Properties of Amino-PEG2-amine-Based Organic Friction Modifiers. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b05333] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wenjing Hu
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaojun Zhang
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Xiangqiong Zeng
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Jiusheng Li
- Laboratory for Advanced Lubricating Materials, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
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16
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Jia W, Tian J, Bai P, Li S, Zeng H, Zhang W, Tian Y. A novel comb-typed poly(oligo(ethylene glycol) methylether acrylate) as an excellent aqueous lubricant. J Colloid Interface Sci 2018; 539:342-350. [PMID: 30594009 DOI: 10.1016/j.jcis.2018.12.085] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/22/2018] [Accepted: 12/22/2018] [Indexed: 11/16/2022]
Abstract
HYPOTHESIS Aqueous lubricants exhibit versatile advantages over oil-based lubricants. However, it still remains a challenge for the aqueous solutions to obtain excellent lubrication properties with high contact pressure on macroscale. EXPERIMENTS In this work, a comb-typed poly(oligo(ethylene glycol) methylether acrylate) (P(OEGMA)) was successfully synthesized via RAFT polymerization. Rheological, morphological and tribological properties of prepared P(OEGMA) aqueous solutions were characterized via a rheometer, cryo-SEM and ball-on-disk tribometer, respectively. FINDINGS The synthesized P(OEGMA) exhibited a uniformly smaller size than that of the commercial linear polyethylene glycol (PEG), leading to reduced viscosities in aqueous solutions. The obtained P(OEGMA) aqueous solutions achieved outstandingly ultralow friction coefficients (μ < 0.01) and a good wear-resistance under high pressure (>300 MPa, two-fold increase than reported in the previous literature). The desirable lubricating performances can be attributed to the well-established running-in period, a good interfacial adsorption property between polymer molecules and solid surfaces, the hydration effect as well as the hydrodynamic effect. The current finding reveals the excellent aqueous lubrication properties possessed by the synthesized comb-typed P(OEGMA), which can broaden the development of aqueous lubricants in practical engineering fields.
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Affiliation(s)
- Wenpeng Jia
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Jinmi Tian
- College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Pengpeng Bai
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Shaowei Li
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Wenling Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
| | - Yu Tian
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
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17
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He X, Lu J, Desanker M, Invergo AM, Lohr TL, Ren N, Lockwood FE, Marks TJ, Chung YW, Wang QJ. Boundary Lubrication Mechanisms for High-Performance Friction Modifiers. ACS APPLIED MATERIALS & INTERFACES 2018; 10:40203-40211. [PMID: 30396273 DOI: 10.1021/acsami.8b11075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We recently reported a new molecular heterocyclic friction modifier (FM) that exhibits excellent friction and wear reduction in the boundary lubrication regime. This paper explores the mechanisms by which friction reduction occurs with heterocyclic alkyl-cyclen FM molecules. We find that these chelating molecules adsorb onto (oxidized) steel surfaces far more tenaciously than conventional FMs such as simple alkylamines. Molecular dynamics simulations argue that the surface coverage of our heterocyclic FM molecules remains close to 100% even at 200 °C. This thermal stability allows the FMs to firmly anchor to the surface, allowing the hydrocarbon chains of the molecules to interact and trap base oil lubricant molecules. This results in thicker boundary film thickness compared with conventional FMs, as shown by optical interferometry measurements.
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Affiliation(s)
| | | | | | | | | | - Ning Ren
- Valvoline Inc., Lexington , Kentucky 40512 , United States
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18
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Sok N, Bernhard C, Désogère P, Goze C, Rousselin Y, Boschetti F, Baglin I, Denat F. Efficient Synthesis of Multifunctional Chelating Agents Based on Tetraazacycloalkanes. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Nicolas Sok
- AgroSup Dijon; PAM UMR A 02.102; Univ. Bourgogne Franche-Comté; 21000 Dijon France
| | - Claire Bernhard
- Institut de Chimie Moléculaire de l'Université de Bourgogne; UMR CNRS 6302; Univ. Bourgogne Franche-Comté; 9 Avenue Alain Savary 21078 Dijon Cedex France
| | - Pauline Désogère
- Institut de Chimie Moléculaire de l'Université de Bourgogne; UMR CNRS 6302; Univ. Bourgogne Franche-Comté; 9 Avenue Alain Savary 21078 Dijon Cedex France
| | - Christine Goze
- Institut de Chimie Moléculaire de l'Université de Bourgogne; UMR CNRS 6302; Univ. Bourgogne Franche-Comté; 9 Avenue Alain Savary 21078 Dijon Cedex France
| | - Yoann Rousselin
- Institut de Chimie Moléculaire de l'Université de Bourgogne; UMR CNRS 6302; Univ. Bourgogne Franche-Comté; 9 Avenue Alain Savary 21078 Dijon Cedex France
| | | | - Isabelle Baglin
- Faculté de santé Département Pharmacie; Pharmacochimie; 28 rue Roger Amsler 49045 Angers Cedex France
| | - Franck Denat
- Institut de Chimie Moléculaire de l'Université de Bourgogne; UMR CNRS 6302; Univ. Bourgogne Franche-Comté; 9 Avenue Alain Savary 21078 Dijon Cedex France
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19
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Liu P, Lu J, Yu H, Ren N, Lockwood FE, Wang QJ. Lubricant shear thinning behavior correlated with variation of radius of gyration via molecular dynamics simulations. J Chem Phys 2018; 147:084904. [PMID: 28863549 DOI: 10.1063/1.4986552] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The shear thinning of a lubricant significantly affects lubrication film generation at high shear rates. The critical shear rate, defined at the onset of shear thinning, marks the transition of lubricant behaviors. It is challenging to capture the entire shear-thinning curve by means of molecular dynamics (MD) simulations owing to the low signal-to-noise ratio or long calculation time at comparatively low shear rates (104-106 s-1), which is likely coincident with the shear rates of interest for lubrication applications. This paper proposes an approach that correlates the shear-thinning phenomenon with the change in the molecular conformation characterized by the radius of gyration of the molecule. Such a correlation should be feasible to capture the major mechanism of shear thinning for small- to moderate-sized non-spherical molecules, which is shear-induced molecular alignment. The idea is demonstrated by analyzing the critical shear rate for squalane (C30H62) and 1-decene trimer (C30H62); it is then implemented to study the behaviors of different molecular weight poly-α-olefin (PAO) structures. Time-temperature-pressure superpositioning (TTPS) is demonstrated and it helps further extend the ranges of the temperature and pressure for shear-thinning behavior analyses. The research leads to a relationship between molecular weight and critical shear rate for PAO structures, and the results are compared with those from the Einstein-Debye equation.
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Affiliation(s)
- Pinzhi Liu
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Jie Lu
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Hualong Yu
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Ning Ren
- Valvoline, Inc., Lexington, Kentucky 40509, USA
| | | | - Q Jane Wang
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, USA
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20
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Cosimbescu L, Demas NG, Robinson JW, Erck RA. Friction- and Wear-Reducing Properties of Multifunctional Small Molecules. ACS APPLIED MATERIALS & INTERFACES 2018; 10:1317-1323. [PMID: 29240999 DOI: 10.1021/acsami.7b13271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nitrogen- and oxygen-containing compounds were designed empirically and subsequently synthesized, and their rheology, friction, and wear performance as multifunctional base oils (MFBOs) were evaluated. Two of the compounds displayed good viscosity/rheology profiles without the addition of polymeric viscosity modifiers, displaying high viscosity indexes (VIs) above 200. Furthermore, all three MFBOs had lower coefficients of friction compared to well-established and accepted benchmarks. The most significant advancement is their impressive wear improvement by a factor of 5.5 to 70 compared to either of the benchmarks, which is attributed to the polar nature of the base oil which promotes boundary lubrication with metal surfaces. Moreover, these compounds were easily synthesized in one step from commercial starting materials. This work demonstrates that a careful design could provide the features/performance/functions of base oil, rheology modifiers (or VI improvers), and antiwear and friction-reducing additives, all-in one molecule.
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Affiliation(s)
- L Cosimbescu
- Pacific Northwest National Laboratory , Richland, Washington 99352, Unites States
| | - N G Demas
- Argonne National Laboratory , Lemont, Illinois 60439, Unites States
| | - J W Robinson
- Pacific Northwest National Laboratory , Richland, Washington 99352, Unites States
| | - R A Erck
- Argonne National Laboratory , Lemont, Illinois 60439, Unites States
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