A novel approach to improve the oil miscibility and incorporate multifunctionality in ionic liquids as lubricant additives

2021 ◽  
Vol 23 (5) ◽  
pp. 3429-3440
Author(s):  
Priya Pandey ◽  
Anthony E. Somers ◽  
Samik K. Hait ◽  
Maria Forsyth ◽  
S. S. V. Ramakumar

Recently ionic liquids (ILs) have shown promising tribological properties as additives in base oils; however their lack of miscibility is a problem, with very few ILs being compatible with lubricant oil formulation (non-polar base oils).

Friction ◽  
2021 ◽  
Author(s):  
Weiwei Tang ◽  
Xuejun Zhu ◽  
Yufeng Li

AbstractAdvances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development. Carbon dots (CDs) have been widely investigated in the domain of lubricant additives owing to their extraordinary tribological properties, in particular, their friction-reducing and anti-wear properties. Metal-doped CDs are a new type of CDs, and their friction-reducing and anti-wear properties are attracting increasing attention. Therefore, a series of CDs doped with various divalent metal ions have been successfully synthesized via one-pot pyrolysis. The tribological properties of the synthesized CDs as water-based lubricant additives are in the following order: Zn-CDs > Cu-CDs ≫ Mg-CDs > Fe-CDs > U-CDs. Specifically, adding 1.0 wt% of Zn-CDs into water-based lubricant results in 62.5% friction and 81.8% wear reduction. Meanwhile, the load-carrying capacity of the water-based lubricant increases from 120 N to at least 500 N. Zn-CDs as an additive have long service life. Additionally, anion-tuned Zn-CDs fabricated via anion exchange exhibit promise as lubricant additives for poly(ethylene glycol). Based on the results of wear scar surface analyses, it is discovered that tribochemical films, primarily composed of iron oxides, nitrides, metal carbonates, zinc oxides, zinc carbonates, organic compounds, and embedded carbon cores, formed on the rubbing surfaces with a thickness of approximately 270 nm when Zn-CDs are used as additives. This film combined with the “ball-bearing” and third-particle effects of Zn-CDs contributed to excellent lubrication performance.


RSC Advances ◽  
2016 ◽  
Vol 6 (53) ◽  
pp. 47753-47760 ◽  
Author(s):  
M. C. Righi ◽  
S. Loehlé ◽  
M. I. De Barros Bouchet ◽  
S. Mambingo-Doumbe ◽  
J. M. Martin

Sulfur reduces the adhesion and shear strength of iron more effectively than phosphorus. The surface chemistry, well described by first principles calculations, impacts macroscale tribological properties.


RSC Advances ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. 4312-4319 ◽  
Author(s):  
Maoquan Xue ◽  
Zhiping Wang ◽  
Feng Yuan ◽  
Xianghua Zhang ◽  
Wei Wei ◽  
...  

TiO2/Ti3C2Tx hybrid nanocomposites were successfully prepared by a liquid phase synthesis technology. The hybrid nanocomposites improve the tribological properties of base oil by mending the surface and formation a uniform tribofilm on the surface.


2021 ◽  
pp. 1-14
Author(s):  
Yufu Xu ◽  
Kequn Sun ◽  
Jingyuan Yu ◽  
Yichen Bao ◽  
Yinghui Dong ◽  
...  

2015 ◽  
Vol 58 (4) ◽  
pp. 577-583 ◽  
Author(s):  
Wang Daji ◽  
Zhu Dachuan ◽  
Li Huafeng ◽  
Chen Guoxu

2017 ◽  
Vol 244 ◽  
pp. 219-225 ◽  
Author(s):  
Ponnekanti Nagendramma ◽  
Praveen K. Khatri ◽  
Gananath D. Thakre ◽  
Suman L. Jain

2020 ◽  
Author(s):  
Alexander Schlaich ◽  
Dongliang Jin ◽  
Lyderic Bocquet ◽  
Benoit Coasne

Abstract Of particular relevance to energy storage, electrochemistry and catalysis, ionic and dipolar liquids display a wealth of unexpected fundamental behaviors – in particular in confinement. Beyond now well-documented adsorption, overscreening and crowding effects1,2,3, recent experiments have highlighted novel phenomena such as unconventional screening4 and the impact of the electronic nature – metallic versus insulating – of the confining surface on wetting/phase transitions5,6. Such behaviors, which challenge existing theoretical and numerical modeling frameworks, point to the need for new powerful tools to embrace the properties of confined ionic/dipolar liquids. Here, we introduce a novel atom-scale approach which allows for a versatile description of electronic screening while capturing all molecular aspects inherent to molecular fluids in nanoconfined/interfacial environments. While state of the art molecular simulation strategies only consider perfect metal or insulator surfaces, we build on the Thomas-Fermi formalism for electronic screening to develop an effective approach that allows dealing with any imperfect metal between these asymptotes. The core of our approach is to describe electrostatic interactions within the metal through the behavior of a `virtual' Thomas-Fermi fluid of charged particles, whose Debye length sets the Thomas-Fermi screening length λ in the metal. This easy-to-implement molecular method captures the electrostatic interaction decay upon varying λ from insulator to perfect metal conditions, while describing very accurately the capacitance behavior – and hence the electrochemical properties – of the metallic confining medium. By applying this strategy to a nanoconfined ionic liquid, we demonstrate an unprecedented wetting transition upon switching the confining medium from insulating to metallic. This novel approach provides a powerful framework to predict the unsual behavior of ionic liquids, in particular inside nanoporous metallic structures, with direct applications for energy storage and electrochemistry.


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