Lina Qiu, Yanan Mao, Aijun Gong, Weiwei Zhang, Yanqiu Cao and Lu Tong
Bdellovibrio bacteriovorus is a gram-negative predatory bacterium which can potentially inhibit microbiologically influenced corrosion by preying on sulfate-reducing bacteria…
Abstract
Purpose
Bdellovibrio bacteriovorus is a gram-negative predatory bacterium which can potentially inhibit microbiologically influenced corrosion by preying on sulfate-reducing bacteria (SRB). However, no researches about the inhibition are reported according to the authors’ knowledge. The purpose of this paper was to investigate the Inhibition effect of B. bacteriovorus on the corrosion of X70 pipeline steel induced by SRB.
Design/methodology/approach
The effect of B. bacteriovorus on the growth of SRB was studied by measuring the optical density at 600 nm (OD600) and sulfate concentration in culture medium. X70 pipeline steel was used as the test material to investigate the anti-corrosion effect of B. bacteriovorus on SRB by conducting electrochemical analysis (including Tafel polarization curves and electrochemical impendence spectroscopy) and weight loss measurement.
Findings
B. bacteriovorus could inhibit the growth of SRB in culture medium by its predation on SRB, which led to decrease of OD600 value and increase of sulfate concentration. The results of electrochemical analysis indicated that B. bacteriovorus had positive inhibition efficiencies on SRB-induced corrosion of X70 pipeline steel. Moreover, corrosion rate of X70 pipeline steel was declined from 19.17 to 3.75 mg·dm-2·day-1 by the presence of B. bacteriovorus.
Originality/value
This is the first report about using B. bacteriovorus to inhibit the corrosion induced by SRB. Compared to other anti-corrosion methods, the microbial inhibition methods exhibit more considerable application value due to its low cost, high efficiency and non-pollution.
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Zhengfeng Cao, Yanqiu Xia and Xiangyu Ge
The purpose of this paper is to synthesize a new kind of conductive grease which possesses a prominent conductive capacity and good tribological properties.
Abstract
Purpose
The purpose of this paper is to synthesize a new kind of conductive grease which possesses a prominent conductive capacity and good tribological properties.
Design/methodology/approach
A two-step method was used to prepare complex lithium-based grease. Ketjen black (KB), acetylene black (AB) and carbon black (CB) were characterized by transmission electron microscope and used as lubricant additives to prepare conductive greases. Conductive capacity was evaluated by a conductivity meter, a surface volume resistivity meter and a circuit resistance meter. Tribological properties were investigated by a reciprocating friction and wear tester (MFT-R4000). The worn surfaces were analyzed by a scanning electron microscope, Raman spectroscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscope.
Findings
The conductive grease prepared with KB has a prominent conductive capacity at room temperature, 100°C and 150°C. Further, this conductive grease also possesses better tribological properties than AB and KB greases. When the concentration of KB is 1.8 Wt.%, the coefficient of friction and wear width reduced by 11 and 14 per cent, respectively.
Originality/value
This work is a new application of nanometer KB as a lubricant additive in grease, which provides a direction for preparing conductive grease. The conductivity and tribology experiments have been carried out though the variation of experiment conductions.
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Zhengfeng Cao, Yanqiu Xia, Chuan Chen, Kai Zheng and Yi Zhang
This paper aims to explore polyaniline (PANI) as a lubricant additive to improve the anti-corrosion and tribological properties of ionic liquids (ILs) for actual applications.
Abstract
Purpose
This paper aims to explore polyaniline (PANI) as a lubricant additive to improve the anti-corrosion and tribological properties of ionic liquids (ILs) for actual applications.
Design/methodology/approach
ILs were synthesized by dissolving lithium salts in synthetic oil and were used as a base oil to prepare ILs-based greases. PANI was used as an additive. The tribological properties were investigated in detail and the anti-corrosion ability was also assessed via salt spray test. After friction test, the worn surfaces were characterized by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy to analyze the lubrication mechanisms.
Findings
PANI not only reduces the corrosion but also improves the friction reduction and anti-wear abilities of the ILs-based greases. The analysis indicates that the protective films generated on the worn surfaces were responsible for the preferable anti-corrosion and tribological properties.
Originality/value
This paper provides an effective approach to improve the anti-corrosion and tribological properties of ILs for actual applications.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0469/
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Yanqiu Xia, Yanan Cao, Xin Feng and Haris M_ P_
The purpose of this paper is to compare the electrical conductivity and tribological properties of magnetron sputtered silver (Ag), copper (Cu) and aluminum (Al) thin films under…
Abstract
Purpose
The purpose of this paper is to compare the electrical conductivity and tribological properties of magnetron sputtered silver (Ag), copper (Cu) and aluminum (Al) thin films under conductive grease lubrication.
Design/methodology/approach
Three types of silver (Ag), copper (Cu) and aluminum (Al) thin films were prepared by magnetron sputtering. Current-carrying friction tests were carried out by a ball-on-plate reciprocating friction and wear tester. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) were used to observe and analyze the worn surface and cross-section morphology of the films.
Findings
Silver and Cu films exhibited good conductivity and tribological properties, which were mainly attributed to the synergy of the protective tribofilm generated by conductive grease, current-induced thermal effect and magnetron sputtered films effect. Al film was worn through. Large pitting storing lubricate were only found in Ag film. Cu film showed a similar surface uniformity with Ag film.
Originality/value
This study provides a reference for the design and application of conductive grease and investigates the current-carrying friction behaviors of magnetron sputtered films as electrical contact materials. The comparison of current-carrying friction behaviors of the three films was rarely covered in previous studies.
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Yanqiu Xia, Chuan Chen, Xin Feng and Zhengfeng Cao
The purpose of this paper is to synthesize a kind of core-shell Ag@polyaniline (Ag@PAN) as a lubricant additive to improve the friction reduction and anti-wear abilities of…
Abstract
Purpose
The purpose of this paper is to synthesize a kind of core-shell Ag@polyaniline (Ag@PAN) as a lubricant additive to improve the friction reduction and anti-wear abilities of lithium-based complex grease.
Design/methodology/approach
The core-shell Ag@PAN was prepared by a simple method and was introduced into the lithium-based complex grease. The typical properties of Ag@PAN were investigated by scanning electron microscopy (SEM), Fourier transforms infrared spectrometer and thermal gravimetric analyzer. The tribological properties were evaluated under different conditions. After the tribological test, the worn surface was analyzed by SEM and X-ray photoelectron spectroscopy to probe the lubrication mechanisms.
Findings
The prepared Ag@PAN could greatly improve the friction reduction and wear resistance of the friction pair under different conditions. The preferable tribological performances were mainly attributed to the synergism of various lubrication mechanisms including “mending effect,” “rolling effect” and lubricating protective film, and so on.
Originality/value
This study synthesizes a new kind of core-shell Ag@PAN as a lubricant additive, and it possesses preferable friction reduction and anti-wear abilities.
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Keywords
Yanqiu Xia, Wenyi Zhang, Zhengfeng Cao and Xin Feng
This paper aims to explore the leaf-surface wax as green lubricant additive and compare the tribological properties between coastal and inland leaf-surface waxes of the same…
Abstract
Purpose
This paper aims to explore the leaf-surface wax as green lubricant additive and compare the tribological properties between coastal and inland leaf-surface waxes of the same species plant.
Design/methodology/approach
The leaf-surface waxes were extracted from the leaves of Robinia pseudoacacia cv. Idaho and Populus nigra in coastal and inland areas, and then the compositions of the four kinds of leaf-surface waxes were characterized using a gas chromatography–mass spectrometry. The tribological properties of these leaf-surface waxes as lubricant additives in the base oil of synthetic ester (SE) were investigated by an MFT-R4000 reciprocating friction and wear tester. As well as the surface morphologies and chemical compositions of the wear scars were characterized by a scanning electron microscope and time-of-flight secondary ion mass spectrometry, respectively.
Findings
The results indicate that all the leaf-surface waxes as additives can effectively improve the friction reduction and anti-wear performances of SE for steel–aluminum friction pairs. Therein, coastal leaf-surface waxes have better tribological performances than inland leaf-surface waxes, which are attributed to that the leaf-surface waxes extracted from coastal plants can form a better protective film on the worn surface throughout the friction process.
Originality/value
This paper investigated a new kind of environmentally friendly lubricant additive and compared the tribological properties of the leaf-surface wax extracted from coastal and inland plants. The associated conclusions can provide a reference to explore the tribological performances of leaf-surface wax as green lubricant additive.
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Yanqiu Xia, Wenhao Chen, Yi Zhang, Kuo Yang and Hongtao Yang
The purpose of this study is to investigate the effectiveness of a composite lubrication system combining polytetrafluoroethylene (PTFE) film and oil lubrication in steel–steel…
Abstract
Purpose
The purpose of this study is to investigate the effectiveness of a composite lubrication system combining polytetrafluoroethylene (PTFE) film and oil lubrication in steel–steel friction pairs.
Design/methodology/approach
A PTFE layer was sintered on the surface of a steel disk, and a lubricant with additives was applied to the surface of the steel disk. A friction and wear tester was used to evaluate the tribological properties and insulation capacity. Fourier transform infrared spectrometer was used to analyze the changes in the composition of the lubricant, and X-ray photoelectron spectroscopy was used to analyze the chemical composition of the worn surface.
Findings
It was found that incorporating the PTFE film with PSAIL 2280 significantly enhanced both the friction reduction and insulation capabilities at the electrical contact interface during sliding. The system consistently achieved ultra-low friction coefficients (COF < 0.01) under loads of 2–4 N and elucidated the underlying lubrication mechanisms.
Originality/value
This work not only confirm the potential of PTFE films in insulating electrical contact lubrication but also offer a viable approach for maintaining efficient and stable low-friction wear conditions.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0222/
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Mingwei Lin, Yanqiu Chen and Riqing Chen
The purpose of this paper is to make a comprehensive analysis of 354 publications about Pythagorean fuzzy sets (PFSs) from 2013 to 2020 in order to comprehensively understand…
Abstract
Purpose
The purpose of this paper is to make a comprehensive analysis of 354 publications about Pythagorean fuzzy sets (PFSs) from 2013 to 2020 in order to comprehensively understand their historical progress and current situation, as well as future development trend.
Design/methodology/approach
First, this paper describes the fundamental information of these publications on PFSs, including their data information, annual trend and prediction and basic features. Second, the most productive and influential authors, countries/regions, institutions and the most cited documents are presented in the form of evaluation indicators. Third, with the help of VOSviewer software, the visualization analysis is conducted to show the development status of PFSs publications at the level of authors, countries/regions, institutions and keywords. Finally, the burst detection of keywords, timezone review and timeline review are exported from CiteSpace software to analyze the hotspots and development trend on PFSs.
Findings
The annual PFSs publications present a quickly increasing trend. The most productive author is Wei Guiwu (China). Wei Guiwu and Wei Cun have the strongest cooperative relationship.
Research limitations/implications
The implication of this study is to provide a comprehensive perspective for the scholars who take a fancy to PFSs, and it is valuable for scholars to grasp the hotspots in this field in time.
Originality/value
It is the first paper that uses the bibliometric analysis to comprehensively analyze the publications on PFSs. It can help the scholars in the field of PFSs to quickly understand the development status and trend of PFSs.
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Tiedan Chen, Yanqiu Xia, Zhilu Liu and Zeyun Wang
The mixture of attapulgite and bentonite was used as a thickener, and polyalphaolefin was used as the base oil to prepare the new lubricating grease. Some solid particles such as…
Abstract
Purpose
The mixture of attapulgite and bentonite was used as a thickener, and polyalphaolefin was used as the base oil to prepare the new lubricating grease. Some solid particles such as Polytetrafluoroethene (PTFE), MoS2, nano-calcium carbonate and graphite were added in the new lubricating grease as anti-wear additives to investigate the tribological sensitivity.
Design/methodology/approach
The new lubricating grease was evaluated by optimol-SRV reciprocating friction and wear tester, and the wear volumes were determined using a MicroXAM-3D. At the same time, the dropping point and the cone penetration were investigated and analyzed. The tribological properties of the new lubricating grease and the sensitivity of some solid lubricating additives to the new lubricating base grease were investigated; pure organic-bentonite and pure organic-attapulgite base grease were used as contrast.
Findings
The new lubricating grease based on the surface-modified bentonite/attapulgite clay base grease was synthesized with a relatively high dropping point, and the mass ratio is 25/75 bentonite/attapulgite clay base grease, having a better tribological performance. MoS2 was used as an anti-wear additive that has good tribological sensitivity to the new lubricating base grease.
Originality/value
The main innovative thought of this work lies in the mixture of attapulgite and bentonite used as thickener. A relevant report is not available at present.
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Kuo Yang, Yanqiu Xia, Wenhao Chen and Yi Zhang
The purpose of this study was to synthesize composite nanoparticles (TiO2@SiO2) via the chemical deposition method and investigate their efficacy as additives in…
Abstract
Purpose
The purpose of this study was to synthesize composite nanoparticles (TiO2@SiO2) via the chemical deposition method and investigate their efficacy as additives in polytetrafluoroethylene (PTFE) lubricating grease. The focus was on examining the frictional and conductive properties of the TiO2@SiO2 grease using a friction tester.
Design/methodology/approach
Composite nanoparticles (TiO2@SiO2) were synthesized using the chemical deposition method and incorporated into PTFE grease. Frictional and conductive properties were evaluated using a friction tester. Surface morphology and chemical composition of wear tracks were analyzed using scanning electron microscope and X-ray photoelectron spectroscopy, respectively.
Findings
Incorporating TiO2@SiO2 at a mass fraction of 1 Wt.% led to a significant reduction in friction coefficient and wear width. The wear depth exhibited a remarkable decrease of 260%, while the contact resistance reached its peak value. This improvement in tribological properties could be attributed to the presence of TiO2@SiO2, where TiO2 served as the core and SiO2 as the shell during the friction process. The high hardness of the SiO2 shell contributed to enhanced load-bearing capacity. In addition, the exceptional insulation properties of SiO2 demonstrated excellent electron-capturing capabilities, resulting in improved friction and insulation performance of the TiO2@SiO2 lubricating grease.
Originality/value
This study demonstrates the potential of TiO2@SiO2 composite nanoparticles as additives in lubricating greases, offering improved friction and insulation performance. The findings provide insights into the design of advanced lubricating materials with enhanced tribological properties and insulation capacity, contributing to the development of more efficient and durable lubrication systems.