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Dong C, Liu Y, Meng Y, Du S, Zhu S, Tian Y, Ma L. Ion-specific ice provides a facile approach for reducing ice friction. J Colloid Interface Sci 2024; 675:451-460. [PMID: 38981254 DOI: 10.1016/j.jcis.2024.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/11/2024]
Abstract
HYPOTHESIS Ice friction plays a crucial role in both basic study and practical use. Various strategies for controlling ice friction have been developed. However, one unsolved puzzle regarding ice friction is the effect of ion-ice interplay on its tribological properties. EXPERIMENTS AND SIMULATIONS Here, we conducted ice friction experiments and summarized the specific effects of hydrated ions on ice friction. By selecting cations and anions, the coefficient of ice friction can be reduced by more than 70 percent. Experimental spectra, low-field nuclear magnetic resonance (LF-NMR), density functional theory (DFT) calculations, and Molecular dynamics (MD) simulations demonstrated that the addition of ions could break the H-bonds in water. FINDINGS The link between the charge density of ions and the coefficients of ice friction was revealed. A part of the ice structure was changed from an ice-like to a liquid-like interfacial water structure with the addition of ions. Lower charge density ions led to weaker ionic forces with the water molecules in the immobilized water layer, resulting in free water molecules increasing in the lubricating layer. This study provides guidance for preparing ice-making solutions with low friction coefficients and a fuller understanding of the interfacial water structure at low temperatures.
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Affiliation(s)
- Chang Dong
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Yuan Liu
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Yanan Meng
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Shaonan Du
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Shicai Zhu
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Yu Tian
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Liran Ma
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China.
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2
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Han T, Xu W, Han J, Adibnia V, He H, Zhang C, Luo J. Counterion Distribution in the Stern Layer on Charged Surfaces. NANO LETTERS 2024; 24:10443-10450. [PMID: 39140834 DOI: 10.1021/acs.nanolett.4c01230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Counterion adsorption at the solid-liquid interface affects numerous applications. However, the counterion adsorption density in the Stern layer has remained poorly evaluated. Here we report the direct determination of surface charge density at the shear plane between the Stern layer and the diffuse layer. By the Grahame equation extension and streaming current measurements for different solid surfaces in different aqueous electrolytes, we are able to obtain the counterion adsorption density in the Stern layer, which is mainly related to the surface charge density but is less affected by the bulk ion concentration. The charge inversion concentration is further found to be sensitive to the ion type and ion valence rather than to the charged surface, which is attributed to the ionic competitive adsorption and ion-ion correlations. Our findings offer a framework for understanding ion distribution in many physical and chemical processes where the Stern layer is ubiquitous.
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Affiliation(s)
- Tianyi Han
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, People's Republic of China
| | - Wanxing Xu
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jie Han
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, People's Republic of China
| | - Vahid Adibnia
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Hongjiang He
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, People's Republic of China
| | - Chenhui Zhang
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jianbin Luo
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, People's Republic of China
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3
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Sang X, Han K, Zhu M, Ma L. Friction Reduction Achieved by Ultraviolet Illumination on TiO 2 Surface. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1680. [PMID: 38612193 PMCID: PMC11012504 DOI: 10.3390/ma17071680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/08/2023] [Accepted: 11/24/2023] [Indexed: 04/14/2024]
Abstract
Controlling friction by light field is a low-cost, low-energy, non-polluting method. By applying ultraviolet light on the surface of photosensitive materials, the properties of the friction pairs or lubricant can be influenced, thus achieving the purpose of reducing friction. In this study, TiO2, an inorganic photosensitive material, was selected to investigate the modulating effect of light fields on friction lubrication when using polyalphaolefin (PAO) base oil as a lubricant, and the modulation law of light fields on the friction lubrication behavior was investigated under different loads (1-8 N), different speeds (20-380 mm/s), and different viscosities (10.1-108.6 mPa·s) of PAO base oil. The experimental results showed that light treatment could reduce the friction coefficient of PAO4 base oil lubrication from 0.034 to 0.016, with a reduction of 52.9% under conditions of 3 N-load and 56.5 mm/s-speed, and the best regulation effect could be achieved under the mixed lubrication condition. After TiO2 was treated with ultraviolet light, due to its photocatalytic property, PAO molecules were oxidized and adsorbed on the TiO2 surface to form an adsorption layer, which avoided the direct contact of rough peaks and thus reduced the friction coefficient. This study combines photosensitivity, photocatalysis, and friction, presenting a method to reduce the friction coefficient by applying a light field without changing the friction pairs or lubricants, which provides a new direction for friction modulation and gives new ideas for practical applications.
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Affiliation(s)
| | | | | | - Liran Ma
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China; (X.S.); (K.H.); (M.Z.)
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4
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Liang H, Zou S, Liu M, Yin T, Xia X, Hua X, Fu Y, Bu Y. Highly Concentrated Electrolyte Superlubricants Enhanced by Interfacial Water Competition Around Chemically Active MgO Additives. ACS APPLIED MATERIALS & INTERFACES 2024; 16:11997-12006. [PMID: 38394677 DOI: 10.1021/acsami.3c15826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
The low concentration of water-based lubricants and the high chemical inertness of the additives involved are often regarded as basic norms in the design of liquid lubricants. Herein, a novel liquid superlubricant of an aqueous solution containing a relatively high concentration of salt, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), is reported for the first time, and the superlubricity stability and load-bearing capacity of the optimized system (MgO0.10/LiTFSI10) are effectively strengthened by the addition of only trace (0.10 wt %) water-chemically active MgO additives. It demonstrates higher applicable loads, lower COF (∼0.004), and stability relative to the base solution. Only a trace amount of MgO additive is needed for the superlubricity, which makes up for the cost and environmental deficiencies of LiTFSI10. The weak interaction region between free water and the outer-layer water of Li+ hydration shells becomes a possible ultralow shear resistance sliding interface; the Mg(OH)2 layer, generated by the reaction of MgO with water, further creates additional weakly interacting interfaces, leading to the formation of an asymmetric contact between the clusters/particles within the hydrodynamic film by moderating the competition between interfacial water and free water, thus achieving high load-bearing macroscopic superlubricity. This study deepens the contribution of electrolyte concentration to ionic hydration and superlubricity due to the low shear slip layer formed by interfacial water competition with water-activated solid additives, providing new insights into the next generation of high load-bearing water-based liquid superlubricity systems.
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Affiliation(s)
- Hongyu Liang
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Shijing Zou
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Manqiang Liu
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Tianqiang Yin
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Xiaojie Xia
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Xijun Hua
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yonghong Fu
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yongfeng Bu
- Institute for Energy Research, Jiangsu University, Zhenjiang 212013, China
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Liang H, Xia X, Liu M, Zou S, Yin T, Li H, Zhang Y, Min C, Bu Y. Competition-Induced Macroscopic Superlubricity of Ionic Liquid Analogues by Hydroxyl Ligands Revealed by in Situ Raman. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:4277-4284. [PMID: 38360538 DOI: 10.1021/acs.langmuir.3c03461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
High load-bearing capacity is one of the crucial indicators for liquid superlubricants to move toward practicality. However, some of the current emerging systems not only have low contact pressures but also are highly susceptible to further degradation due to water adsorption and even superlubricity failure. Herein, a novel choline chloride-based ionic liquid analogues (ILAs) of a superlubricant with triethanolamine (TEOA) as the H-bond donor is reported for the first time; it obtains an ultralow coefficient of friction (0.005) and high load-bearing capacity (360 MPa, more than 2 times that of similar systems) due to adsorption of a small amount of water (<5 wt %) from the air. In situ Raman combined with 1H NMR and FTIR techniques reveals that adsorbed water competes with the hydroxyl group of TEOA for coordination with Cl-, leading to the conversion of some strong H-bonds to weak H-bonds in ILAs; the localized strong H-bonds and weak H-bonds endow the ILAs with high load-bearing capacity and the formation of ultralow shear-resistance sliding interfaces, respectively, under the shear motion. This study proposes a strategy to modulate the interactions between liquid species using adsorbed water from air as a competing ligand, which provides new insights into the design of ILA-based macroscopic liquid superlubricants with a high load-bearing capacity.
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Affiliation(s)
- Hongyu Liang
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Xiaojie Xia
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Manqiang Liu
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Shijing Zou
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Tianqiang Yin
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Hongfei Li
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yanhu Zhang
- Institute of Advanced Manufacturing and Modern Equipment Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Chunying Min
- School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yongfeng Bu
- Institute for Energy Research, Jiangsu University, Zhenjiang 212013, China
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Han T, Zhao M, Sun C, Zhao R, Xu W, Zhang S, Singh S, Luo J, Zhang C. Macroscale Superlubricity of Hydrated Anions in the Boundary Lubrication Regime. ACS APPLIED MATERIALS & INTERFACES 2023; 15:42094-42103. [PMID: 37625155 DOI: 10.1021/acsami.3c09277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
Cations can achieve excellent hydration lubrication at smooth interfaces under both microscale and macroscale conditions due to the boundary layer composed of hydration shells surrounding charges, but what about anions? Commonly used friction pairs are negatively charged at the solid/solution interface. Achieving anionic adsorption through constructing positively charged surfaces is a prerequisite for studying the hydration lubrication of anions. Here we report the hydration layer composed of anions adsorbed on the positively charged polymer/sapphire interface at acidic electrolyte solutions with pH below the isoelectric point, which contributes to the hydration lubrication of anions. Strongly hydrated anions (for the case of SO42-) exhibit stable superlubricity comparable to cations, with strikingly low boundary friction coefficient of 0.003-0.007 under contact pressures above 15 MPa without a running-in period. The hydration lubrication performance of anions is determined by both the ionic hydration strength and ion adsorption density based on the surface potential and tribological experiments. The results shed light on the role of anions in superlubricity and hydration lubrication, which may be relevant for understanding the lubrication mechanism and improving lubrication performance in acidic environments, for example, in acid pumps, sealing rings of compressors for handling acidic media, and processing devices of nuclear waste.
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Affiliation(s)
- Tianyi Han
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Mingbo Zhao
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Chuan Sun
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Ruiqi Zhao
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Wanxing Xu
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Shumin Zhang
- Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms, Beijing Institute of Control Engineering, Beijing 100094, China
| | - Sudesh Singh
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
- Department of Mechanical Engineering, Sharda School of Engineering and Technology, Sharda University, Greater Noida 201310, India
| | - Jianbin Luo
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
| | - Chenhui Zhang
- State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China
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7
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He Z, Mu L, Wang N, Su J, Wang Z, Luo M, Zhang C, Li G, Lan X. Design, fabrication, and applications of bioinspired slippery surfaces. Adv Colloid Interface Sci 2023; 318:102948. [PMID: 37331090 DOI: 10.1016/j.cis.2023.102948] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 05/30/2023] [Accepted: 06/10/2023] [Indexed: 06/20/2023]
Abstract
Bioinspired slippery surfaces (BSSs) have attracted considerable attention owing to their antifouling, drag reduction, and self-cleaning properties. Accordingly, various technical terms have been proposed for describing BSSs based on specific surface characteristics. However, the terminology can often be confusing, with similar-sounding terms having different meanings. Additionally, some terms fail to fully or accurately describe BSS characteristics, such as the surface wettability of lubricants (hydrophilic or hydrophobic), surface wettability anisotropy (anisotropic or isotropic), and substrate morphology (porous or smooth). Therefore, a timely and thorough review is required to clarify and distinguish the various terms used in BSS literature. This review initially categorizes BSSs into four types: slippery solid surfaces (SSSs), slippery liquid-infused surfaces (SLISs), slippery liquid-like surfaces (SLLSs), and slippery liquid-solid surfaces (SLSSs). Because SLISs have been the primary research focus in this field, we thoroughly review their design and fabrication principles, which can also be applied to the other three types of BSS. Furthermore, we discuss the existing BSS fabrication methods, smart BSS systems, antifouling applications, limitations of BSS, and future research directions. By providing comprehensive and accurate definitions of various BSS types, this review aims to assist researchers in conveying their results more clearly and gaining a better understanding of the literature.
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Affiliation(s)
- Zhoukun He
- Institute for Advanced Study, Research Center of Composites & Surface and Interface Engineering, Chengdu University, Chengdu 610106, China
| | - Linpeng Mu
- Institute for Advanced Study, Research Center of Composites & Surface and Interface Engineering, Chengdu University, Chengdu 610106, China; School of Mechanical Engineering, Chengdu University, Chengdu 610106, China
| | - Na Wang
- Institute for Advanced Study, Research Center of Composites & Surface and Interface Engineering, Chengdu University, Chengdu 610106, China; School of Mechanical Engineering, Chengdu University, Chengdu 610106, China
| | - Jie Su
- Institute for Advanced Study, Research Center of Composites & Surface and Interface Engineering, Chengdu University, Chengdu 610106, China; School of Mechanical Engineering, Chengdu University, Chengdu 610106, China
| | - Zhuo Wang
- Institute for Advanced Study, Research Center of Composites & Surface and Interface Engineering, Chengdu University, Chengdu 610106, China; School of Mechanical Engineering, Chengdu University, Chengdu 610106, China
| | - Mingdong Luo
- Luzhou Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, The Affiliated Stomatological Hospital of Southwest Medical University, Luzhou 646000, China; Institute of Stomatology, Southwest Medical University, Luzhou 646000, China
| | - Chunle Zhang
- Kidney Research Institute, Division of Nephrology, West China Hospital of Sichuan University, Chengdu 610041, China.
| | - Guangwen Li
- Luzhou Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, The Affiliated Stomatological Hospital of Southwest Medical University, Luzhou 646000, China; Institute of Stomatology, Southwest Medical University, Luzhou 646000, China.
| | - Xiaorong Lan
- Luzhou Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, The Affiliated Stomatological Hospital of Southwest Medical University, Luzhou 646000, China; Institute of Stomatology, Southwest Medical University, Luzhou 646000, China.
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8
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Du C, Yu T, Zhang L, Deng H, Shen R, Li X, Feng Y, Wang D. Macroscale Superlubricity with Ultralow Wear and Ultrashort Running-In Period (∼1 s) through Phytic Acid-Based Complex Green Liquid Lubricants. ACS APPLIED MATERIALS & INTERFACES 2023; 15:10302-10314. [PMID: 36755437 DOI: 10.1021/acsami.2c22402] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Liquid superlubricity has attracted much attention, due to its ability to significantly reduce friction on the macroscale. However, the severe wear caused by the long running-in period is still one of the bottlenecks restricting the practical application of liquid superlubricating materials. In this work, the obtained polyethylene glycol-phytic acid (PEG-PA) composite liquid lubricants showed outstanding superlubricating properties (μ ≈ 0.006) for Si3N4/glass friction pairs with an ultrashort running-in period (∼1 s) under high Hertzian contact pressure of ∼758 MPa. More importantly, even after up to 12 h (∼700 m of travel), only about 100 nm deep wear scars were found on the surface of the glass sheet (wear rate = 2.51× 10-9 mm3 N-1 m-1). From the molecular point of view, the water molecules anchored between the two friction pairs have extremely low shear force during the friction process, and the strong hydrogen bond interaction between PEG and PA greatly improves the bearing capacity of the lubricant. This work addresses the challenge of liquid superlubricant simultaneously exhibiting low shear force and high load-carrying capacity and makes it possible to obtain liquid superlubrication performance with an extremely short running-in time.
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Affiliation(s)
- Changhe Du
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tongtong Yu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Qingdao Center of Resource Chemistry and New Materials, Qingdao 266104, China
| | - Liqiang Zhang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Qingdao Center of Resource Chemistry and New Materials, Qingdao 266104, China
| | - Haoyu Deng
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruilin Shen
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xiaojuan Li
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yange Feng
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Qingdao Center of Resource Chemistry and New Materials, Qingdao 266104, China
| | - Daoai Wang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Qingdao Center of Resource Chemistry and New Materials, Qingdao 266104, China
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Kreivaitis R, Kupčinskas A, Gumbytė M, Treinytė J. Tribological properties of bis(2-hydroxyethyl)ammonium oleate in glycerol and polyethylene glycol aqueous solutions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Wen X, Bai P, Meng Y, Ma L, Tian Y. High-Temperature Superlubricity Realized with Chlorinated-Phenyl and Methyl-Terminated Silicone Oil and Hydrogen-Ion Running-in. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:10043-10051. [PMID: 35915968 DOI: 10.1021/acs.langmuir.2c01523] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Ceramic friction pairs lubricated with chlorinated-phenyl and methyl-terminated silicone oil (CPSO) systems have potential applications in the aerospace industry. In this study, the effects of the running-in process and temperature on the lubricating performance of CPSO were investigated. The superlubricity of Si3N4/sapphire lubricated with CPSO was realized at >190 °C after H+-ion running-in. The mechanism of this high-temperature superlubricity was investigated by determining the stable adsorption configurations and adsorption energies of CPSO on different surfaces using density functional theory calculations. Compared with that on the Si3N4 surface, the adsorption capacity of CPSO on the hydroxylated SiO2 surface generated by H+-ion running-in increased, whereas the steric hindrance decreased. The viscosity-temperature curve of CPSO was measured, wherein the viscosity and pressure-viscosity coefficient of CPSO considerably decreased with increasing temperature, leading to high-temperature superlubricity in a wide speed/load range. This is the first paper to report oil-based superlubricity at temperatures of 190 °C, or even higher-temperature conditions. Furthermore, it provides guidance for the use of ceramic-CPSO systems in high-temperature conditions, including in the aerospace industry.
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Affiliation(s)
- Xiangli Wen
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Pengpeng Bai
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Yonggang Meng
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Liran Ma
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Yu Tian
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
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11
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Liu M, Zhang C, Chen J, Liu Z, Cheng Y, Wu X. Mechanisms of cation-induced superlubricity transition of poly(vinylphosphonic acid) coatings. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119117] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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12
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Fang H, Li Y, Zhang S, Ding Q, Hu L, Lu K. The superior lubricating performance and unique mechanism of oil-soluble protic ionic liquids with short alkyl chains. J Colloid Interface Sci 2022; 623:257-266. [PMID: 35588633 DOI: 10.1016/j.jcis.2022.04.174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 12/16/2022]
Abstract
HYPOTHESIS Ionic liquids (ILs), as lubricant additives, can greatly improve the lubricating behavior of the frictional interfaces. However, it is urgent to explore ILs with good oil solubility in nonpolar oils, and it is necessary to further study and verify the lubrication mechanism of ILs from the perspective of alkyl chain length. EXPERIMENTS Five protic ILs (PILs) with varying alkyl chain lengths were synthesized by proton transfer method. As additives in PAO oil, their tribological properties were investigated on SRV-V tester. Through molecular dynamics simulation, the adsorption behavior of PILs at the frictional interface was illustrated. FINDINGS The tribological properties of base oil could be significantly improved by adding PIL additives, but interestingly, PILs with short-chain anions showed better lubricating performance, which contradicted most of the early findings. Further analyses revealed that PILs achieved effective lubrication by the tribochemical interaction between anions and frictional interface, and the formation of cationic protective layer. However, PILs with shorter-chain anions form a denser protective layer that can better support the interfacial anions to participate in tribochemical reactions and thus abnormally exhibit superior lubricating performance than those with longer-chain anions.
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Affiliation(s)
- Hongling Fang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100039, PR China
| | - Yi Li
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; Qingdao Center of Resource Chemistry & New Materials, Qingdao 266071, PR China
| | - Songwei Zhang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; Qingdao Center of Resource Chemistry & New Materials, Qingdao 266071, PR China.
| | - Qi Ding
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; Qingdao Center of Resource Chemistry & New Materials, Qingdao 266071, PR China
| | - Litian Hu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
| | - Kuan Lu
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, PR China; National Energy Center for Coal to Clean Fuels, Synfuels China Co., Ltd., Huairou District, Beijing 101400, PR China
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13
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Feng S, Liu Y, Li J, Wen S. Superlubricity Achieved with Zwitterionic Brushes in Diverse Conditions Induced by Shear Actions. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00430] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shaofei Feng
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Jinjin Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Shizhu Wen
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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Wen X, Bai P, Li Y, Cao H, Li S, Wang B, Fang J, Meng Y, Ma L, Tian Y. Effects of Abrasive Particles on Liquid Superlubricity and Mechanisms for Their Removal. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:3628-3636. [PMID: 33733780 DOI: 10.1021/acs.langmuir.0c03607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Liquid superlubricity results in a near-frictionless lubrication state, which can greatly reduce friction and wear under aqueous conditions. However, during the running-in process, a large number of abrasive particles are generated, and because these may lead to a breakdown in superlubricity performance, they should be effectively removed. In this paper, the morphology, size, and composition of abrasive particles were verified using scanning electron microscopy with energy-dispersive X-ray spectroscopy, and their influence on liquid superlubricity was explored through friction tests. Subsequently, different solvents were used to remove the abrasive particles, and the optimal cleaning process was determined by macroscopic tribo-tests and microscopic analysis. Finally, droplet-spreading experiments and a force-curve analysis were carried out to understand the abrasive-particle removal mechanism by different solvents. We found that SiO2 was the main component in the abrasive particles, and micron-sized SiO2 particles resulted in random "wave peaks" in the coefficient of friction and, thus, the superlubricity. Absolute ethanol + ultrapure water was determined to be the optimal solvent for effectively removing abrasive particles from friction-pair surfaces and helped the lubricant in exhibiting an ultralow friction coefficient for long periods of time. We proposed a "wedge" and "wrap" model to explain the abrasive-particle removal mechanism of different solvents. The SiO2 removal mechanism outlined in this study can be applied under aqueous conditions to improve the stability and durability of liquid superlubricity in practical engineering applications.
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Affiliation(s)
- Xiangli Wen
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Pengpeng Bai
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Yuanzhe Li
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Hui Cao
- 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
| | - Bin Wang
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Jingbo Fang
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Yonggang Meng
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Liran Ma
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Yu Tian
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
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