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Wang B, Lian J, Jing M, Lu H. Synthesis of Eco-Friendly Carbon Dots as Self-Repairing Additives of Polyalphaolefin by Means of a Green Solvation Effect. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:15756-15765. [PMID: 36472078 DOI: 10.1021/acs.langmuir.2c02648] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The eco-friendly menthol-modified carbon dots (CDs-Menth) were synthesized for the first time and exhibited the particularly promising application potential as additives of polyalphaolefin (PAO4). On the one hand, the CDs-Menth could be well dispersed into PAO4 with excellent and long-term dispersion stability via a convenient and green mean, that is, the solvation effect of petroleum ether. This mean was far more advanced to current strategies such as chemical modifications and adding dispersants. On the other hand, the CDs-Menth as additives possessed not only the duty-bound merits such as the distinguished friction-reducing, anti-wear, and load-carrying functions, but also an amazing ability of self-repairing effect. The repairing rate of lower disc in the ball-on-disc friction pair lubricated with CDs-Menth/PAO4 lubricant (2.5 wt %) was about 19.3% if the friction duration was prolonged from 20 to 120 min. Meanwhile, the wear volume reduction for PAO4 caused by CDs-Menth remarkably increased from 43.5 to 74.6%. By virtue of the self-repairing effect, the CDs-Menth could form the tough and tensile boundary lubrication films on the rubbing surfaces, not only tremendously reducing the friction and wear of friction pair, but also hopefully protecting the friction interfaces from the potential oxidation and corrosion.
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Affiliation(s)
- Baogang Wang
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Jingcun Lian
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Minjia Jing
- Drilling & Production Technology Research Institute of CCDC, Guanghan 618300, P. R. China
| | - Hongsheng Lu
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
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2
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Vyavhare K, Timmons RB, Erdemir A, Edwards BL, Aswath PB. Robust Interfacial Tribofilms by Borate- and Polymer-Coated ZnO Nanoparticles Leading to Improved Wear Protection under a Boundary Lubrication Regime. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1743-1759. [PMID: 33502870 DOI: 10.1021/acs.langmuir.0c02985] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This work reports on the development of borate- and methacrylate-polymer-coated zinc oxide nanoparticles (ZnOBM) via a plasma polymerization technique to replace the harmful conventional antiwear additive zinc dialkyl dithiophosphate (ZDDP) in automotive lubricants. Here, the tribochemistry across the interfaces formed between sliding ferrous surfaces and coated and uncoated ZnO nanoparticles is thoroughly studied from the perspective of elucidating the tribofilm formation, wear, and friction performance of a novel ZnOBM-based nanolubricant. Tribological tests conducted under a boundary lubrication regime revealed that oil formulations containing only ZnOBM nanoadditives and a mixture of ZnOBM with a low amount of ZDDP (350 ppm of P) significantly improve wear performance (up to 95%) compared to the base oil. Electrical contact resistance results acquired in situ during tribological tests demonstrated that lubricants containing ZnOBM nanoparticles at sliding interfaces undergo tribochemical reactions to form stable tribofilms that reduce friction and wear. Atomic force microscopy (AFM), X-ray absorption near-edge spectroscopy (XANES), and X-ray photoelectron spectroscopy (XPS) analysis revealed that ZnOBM nanoparticles, by themselves, form patchy interfacial tribofilms containing iron borate, boron oxide, and zinc oxide and lead to superior tribological performance. Interestingly, ZnOBM nanoparticles interact synergistically with ZDDP to form a hierarchical interface of boron-doped tribofilms, with zinc-iron polyphosphates at the surface and iron oxide, zinc and iron sulfides in the bulk. These encouraging results suggest the potential effective use of the ZnOBM nanoparticles to significantly reduce harmful levels of ZDDP (350 ppm) in the engine oil without compromising the antifriction and antiwear performance and to develop eco-friendly high-performance lubricant additives.
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Affiliation(s)
- Kimaya Vyavhare
- Materials Science and Engineering, University of Texas at Arlington, P.O. Box 19031, Arlington, Texas 76019, United States
| | - Richard B Timmons
- Chemistry and Biochemistry, University of Texas at Arlington, P.O. Box 19065, Arlington, Texas 76019, United States
| | - Ali Erdemir
- Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Brian L Edwards
- Chemistry and Biochemistry, University of Texas at Arlington, P.O. Box 19065, Arlington, Texas 76019, United States
| | - Pranesh B Aswath
- Materials Science and Engineering, University of Texas at Arlington, P.O. Box 19031, Arlington, Texas 76019, United States
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Dias HVR, Palehepitiya Gamage CS, Jayaratna NB, Hettiarachchi CV. Mixed ligand complexes of silver( i) supported by highly fluorinated pyrazolates, and chelating and bridging N-heterocycles. NEW J CHEM 2020. [DOI: 10.1039/d0nj04007j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A range of silver complexes featuring all nitrogen coordination environments involving pyrazolates and chelating and non-chelating bidentate N-heterocycles are reported.
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Affiliation(s)
- H. V. Rasika Dias
- Department of Chemistry and Biochemistry
- University of Texas at Arlington
- Arlington
- USA
| | | | - Naleen B. Jayaratna
- Department of Chemistry and Biochemistry
- University of Texas at Arlington
- Arlington
- USA
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Zhao J, Li Y, He Y, Luo J. In Situ Green Synthesis of the New Sandwichlike Nanostructure of Mn 3O 4/Graphene as Lubricant Additives. ACS APPLIED MATERIALS & INTERFACES 2019; 11:36931-36938. [PMID: 31356745 DOI: 10.1021/acsami.9b08993] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Nanoparticles and two-dimensional (2D) nanosheets are well-investigated as lubricant additives, which can significantly reduce frictional energy consumption. However, the tribological properties of the additives will deteriorate because of the occurrence of aggregation in the lubricant and the difficulty in entering the frictional contact area. In the present work, the new sandwichlike nanostructure of Mn3O4 nanoparticles and graphene nanosheets (Mn3O4@G) has been developed by an in situ green synthesis method; i.e., the impurities of Mn2+ ions in crude graphite oxide as the precursor are directly transferred into Mn3O4 precipitate between the graphene sheets. The graphene has a lamellar structure without folds and wrinkles, and the Mn3O4 nanoparticles are not only uniformly anchored on the graphene surfaces but also intercalated in the layers of the graphene nanosheets. The Mn3O4@G exhibits excellent tribological properties and high stability because of a synergistic lubrication effect between the graphene nanosheets and the Mn3O4 nanoparticles. Even at an ultralow concentration (0.075 wt %) and a high temperature of 125 °C, the friction coefficient and the wear depth have been reduced by 75% and 97% compared with base oil, respectively. The synthesis method and the Mn3O4@G nanocomposite have significant potential in various tribological applications for saving energy.
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Affiliation(s)
- Jun Zhao
- College of Mechanical and Electrical Engineering , Beijing University of Chemical Technology , Beijing 100029 , China
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Yingru Li
- Institute of Materials , China Academy of Engineering Physics , PO Box 9071-11, Mianyang , Sichuan 621908 , China
| | - Yongyong He
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
| | - Jianbin Luo
- State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China
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Cored J, Crespo O, Serrano JL, Elduque A, Giménez R. Decisive Influence of the Metal in Multifunctional Gold, Silver, and Copper Metallacycles: High Quantum Yield Phosphorescence, Color Switching, and Liquid Crystalline Behavior. Inorg Chem 2018; 57:12632-12640. [DOI: 10.1021/acs.inorgchem.8b01778] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jorge Cored
- Instituto de Ciencia de Materiales de Aragón (ICMA), Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Zaragoza - CSIC, 50009 Zaragoza, Spain
| | - Olga Crespo
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza - CSIC, 50009 Zaragoza, Spain
| | - José Luis Serrano
- Instituto de Ciencia de Materiales de Aragón (ICMA), Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Zaragoza - CSIC, 50009 Zaragoza, Spain
- Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - Anabel Elduque
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza - CSIC, 50009 Zaragoza, Spain
| | - Raquel Giménez
- Instituto de Ciencia de Materiales de Aragón (ICMA), Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Zaragoza - CSIC, 50009 Zaragoza, Spain
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Seymour BT, Fu W, Wright RAE, Luo H, Qu J, Dai S, Zhao B. Improved Lubricating Performance by Combining Oil-Soluble Hairy Silica Nanoparticles and an Ionic Liquid as an Additive for a Synthetic Base Oil. ACS APPLIED MATERIALS & INTERFACES 2018; 10:15129-15139. [PMID: 29619826 DOI: 10.1021/acsami.8b01579] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This article reports on improved lubricating performance by combining oil-soluble poly(lauryl methacrylate) brush-grafted silica nanoparticles (hairy NPs or HNP) and an oil-miscible phosphonium-phosphate ionic liquid (IL) as a friction-reducing additive for a polyalphaolefin (PAO) oil. The HNP was synthesized by surface-initiated reversible addition-fragmentation chain transfer polymerization. At a total concentration of 2% and sufficiently high individual concentrations for HNP and IL in PAO, high-contact stress, ball-on-flat reciprocating tribological tests showed that the friction decreased by up to 23% compared with 2% HNP alone in PAO and by up to 35% compared to the PAO mixed with 2% IL. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy (XPS) analysis revealed that the tribofilm formed from the PAO containing 1% HNP + 1% IL was enriched with both Si and P, indicating that both hairy NPs and IL were involved in the tribochemical reactions. In addition, the O 1s and Si 2p peaks in the core-level XPS spectra exhibited significant shifts for the mixture of 1% HNP + 1% IL compared to those for 2% HNP, suggesting the possible formation of new covalent bonds. These results indicated that HNP and IL reacted with each other and also with the metal substrate during the rubbing process, which likely strengthened the tribofilm and its bonding with the substrate and thus further improved the lubrication.
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Affiliation(s)
- Bryan T Seymour
- Department of Chemistry , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Wenxin Fu
- Department of Chemistry , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Roger A E Wright
- Department of Chemistry , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | | | | | - Sheng Dai
- Department of Chemistry , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Bin Zhao
- Department of Chemistry , University of Tennessee , Knoxville , Tennessee 37996 , United States
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Kumara C, Luo H, Leonard DN, Meyer HM, Qu J. Organic-Modified Silver Nanoparticles as Lubricant Additives. ACS APPLIED MATERIALS & INTERFACES 2017; 9:37227-37237. [PMID: 28968059 DOI: 10.1021/acsami.7b13683] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Advanced lubrication is essential in human life for improving mobility, durability, and efficiency. Here we report the synthesis, characterization, and evaluation of two groups of oil-suspendable silver nanoparticles (NPs) as candidate lubricant additives. Two types of thiolated ligands, 4-(tert-butyl)benzylthiol (TBBT) and dodecanethiol (C12), were used to modify Ag NPs in two size ranges, 1-3 and 3-6 nm. The organic surface layer successfully suspended the Ag NPs in a poly-alpha-olefin (PAO) base oil with concentrations up to 0.19-0.50 wt %, depending on the particle type. Use of the Ag NPs in the base oil reduced friction by up to 35% and wear by up to 85% in boundary lubrication. The two TBBT-modified NPs produced a lower friction coefficient than the C12-modified one, while the two larger NPs (3-6 nm) had better wear protection than the smaller one (1-3 nm). Results suggested that the molecular structure of the organic ligand might have a dominant effect on the friction behavior, while the NP size could be more influential in the wear protection. No mini-ball-bearing or surface smoothening effects were observed in the Stribeck scans. Instead, the wear protection in boundary lubrication was attributed to the formation of a silver-rich 50-100 nm thick tribofilm on the worn surface, as revealed by morphology examination and composition analysis from both the top surface and cross section.
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Affiliation(s)
- Chanaka Kumara
- Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States
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Desanker M, He X, Lu J, Liu P, Pickens DB, Delferro M, Marks TJ, Chung YW, Wang QJ. Alkyl-Cyclens as Effective Sulfur- and Phosphorus-Free Friction Modifiers for Boundary Lubrication. ACS APPLIED MATERIALS & INTERFACES 2017; 9:9118-9125. [PMID: 28219241 DOI: 10.1021/acsami.6b15608] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Modern automotive engines operate at higher power densities than ever before, driving a need for new lubricant additives capable of reducing friction and wear further than ever before while not poisoning the catalytic converter. Reported in this paper is a new class of molecular friction modifier (FM), represented by 1,4,7,10-tetradodecyl-1,4,7,10-tetraazacyclododecane (1a), designed to employ thermally stable, sulfur- and phosphorus-free alkyl-substituted nitrogen heterocycles with multiple nitrogen centers per molecule. The multiple nitrogen centers enable cooperative binding to a surface which provides strong surface adsorption and lubricant film durability in the boundary lubrication (BL) regime. A 1 wt % loading of the cyclen FM 1a in Group III base oil exhibits strong surface adsorption, leading to excellent reductions in friction (70%) and wear (95%) versus the pure Group III oil across a wide temperature range. The lubricant with the new FM additive also outperforms two commercially available noncyclic amine-based FMs and a fully formulated commercial 5W30 motor oil.
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Affiliation(s)
- Michael Desanker
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Xingliang He
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Jie Lu
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Pinzhi Liu
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - David B Pickens
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Massimiliano Delferro
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Tobin J Marks
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Yip-Wah Chung
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Q Jane Wang
- Department of Chemistry, ‡Department of Mechanical Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
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