Tribological study of TiO2 nanoparticles modified with stearic acid as additives in lithium grease

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hong Zhang ◽  
Sheng Han ◽  
Wenjing Hu ◽  
Jiusheng Li
Keyword(s):  
Surface Modification ◽  
Electron Microscope ◽  
Stearic Acid ◽  
Metal Nanoparticles ◽  
Tio2 Nanoparticles ◽  
Tribological Properties ◽  
Lithium Grease ◽  
Content Type ◽  
Prepared Nanoparticles ◽  
Steel Balls

Purpose The purpose of this paper is to improve the properties of metal nanoparticles which are easy to agglomerate and hard to disperse evenly, thus limiting the application of metal nanoparticles in grease. A novel technology was proposed for modifying metal oxide to improve the dispersibility of nanoparticles. Design/methodology/approach SA-TiO2 nanoparticles were synthesized using an in-situ esterification method followed by surface modification with stearic acid. The microstructure of the nanoparticles was characterized by scanning electron microscope, transmission electron microscope and Fourier transform infrared spectroscopy and their thermal stability was evaluated by thermogravimetric analyzer. The tribological properties of the SA-TiO2 nanoparticles as additives in lithium grease were evaluated with a four-ball tester and TE77 reciprocating friction tester. The worn surfaces of the steel balls were investigated by EDS and XPS. Findings The prepared nanoparticles can be well dispersed in the lithium grease and possess much better tribological properties compared to traditional nanoparticles. The results indicated that the excellent tribological performance of SA-TiO2 was attributed to the chemical reaction film composing of Fe2O3, iron oxide and other organic compounds. Originality/value This paper provides a method to prevent the agglomeration of nano-TiO2 by surface modification with stearic acid. And the prepared nanoparticles can effectively improve the tribology performance of lithium grease.

Synthesis and tribological properties of nanogrease

2018 ◽  
Vol 70 (3) ◽  
pp. 512-518 ◽  
Author(s):  
Alaa Mohamed ◽  
Mohamed Hamdy ◽  
Mohamed Bayoumi ◽  
Tarek Osman
Keyword(s):  
Electron Microscopy ◽  
Tribological Properties ◽  
Power Efficiency ◽  
New Technologies ◽  
Mechanical Equipment ◽  
Content Type ◽  
Base Oil ◽  
X Ray ◽  
Transmission Electron ◽  
Steel Balls

Purpose To enhance the tribological properties of nanogrease, one of the new technologies was used to synthesize a nanogrease having carbon nanotubes (CNTs) nanoparticles (NPs) with different concentrations. The microstructures of the synthesized NPs were characterized and evaluated by x-ray diffraction spectroscopy (XRD) and transmission electron microscopy (TEM). Tribological properties of the nanogrease were evaluated using a four-ball tester. The worn surface of four steel balls was investigated by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). Design/methodology/approach Grease was dissolved in chloroform (10 Wt.%), at 25 °C for 1 h. In parallel, functionalized CNTs with different volume concentrations (0.5, 1, 2 and 3 Wt.%) were dispersed in N, N-dimethylformamide. The mixture was stirred for 15 min and then sonicated (40 kHz, 150 W) for 30 min. After that, the mixture was added to the grease solution and magnetically stirred for 15 min and then sonicated for 2 h. Findings The results suggested that CNTs can enhance the antiwear and friction properties of nanogrease at 0.5 Wt.% CNTs to about 57 and 48 per cent, respectively. In addition, the weld load of the base oil containing 0.5 Wt.% CNTs was improved by 17 per cent compared with base grease. Originality/value This work describes the inexpensive and simple fabrication of nanogrease for improving the properties of lubricants, which improve power efficiency and extend lifetimes of mechanical equipment.

Synthesis and Tribological Properties of Stearic Acid-Modified Anatase (TiO2) Nanoparticles

2010 ◽  
Vol 41 (2) ◽  
pp. 409-416 ◽  
Author(s):  
Ling Zhang ◽  
Lei Chen ◽  
Hongqi Wan ◽  
Jianmin Chen ◽  
Huidi Zhou
Keyword(s):  
Stearic Acid ◽  
Tio2 Nanoparticles ◽  
Tribological Properties ◽  
Anatase Tio2

Conductive capacity and tribological properties of several carbon materials in conductive greases

2016 ◽  
Vol 68 (5) ◽  
pp. 577-585 ◽  
Author(s):  
Zhengfeng Cao ◽  
Yanqiu Xia ◽  
Xiangyu Ge
Keyword(s):  
Electron Microscope ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Volume Resistivity ◽  
Lubricant Additive ◽  
Step Method ◽  
Content Type ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Complex Lithium

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.

Tribological properties of zirconium phosphate-quinoline compound as an additive in lithium grease

2018 ◽  
Vol 70 (8) ◽  
pp. 1487-1493
Author(s):  
Wenxing Niu ◽  
Lei Liu ◽  
Hong Xu ◽  
Jinxiang Dong
Keyword(s):  
Tribological Properties ◽  
Direct Contact ◽  
Three Dimensional ◽  
Lubricant Additive ◽  
High Load ◽  
Lithium Grease ◽  
Content Type ◽  
Post Test ◽  
Long Time ◽  
Time Test

Purpose The purpose of this paper is to study the tribological properties of (C9H8N)4(H2O)4[Zr8P12O40(OH)8F8] (designated as ZrPOF-Q1) used as an additive in lithium grease. Design/methodology/approach The tribological properties of ZrPOF-Q1 as an additive in the lithium grease were evaluated with a four-ball tester. To understand the lubrication mechanism, post-test characterization of the contact tracks was performed via three-dimensional (3D) optical profiler, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Findings The results reveal that ZrPOF-Q1 exhibits good performance in anti-wear, friction-reducing and load-carrying capacity. The action mechanism is estimated through analysis of the worn surface with SEM, EDS and 3D. The results indicate that ZrPOF-Q1 can adhere on the substrate, protecting the rubbed surfaces from a direct contact, even under high load for a long-time test. ZrPOF-Q1 can adhere on the substrate, protecting the rubbed surfaces from a direct contact, even under high load for a long-time test. Originality/value This work illustrates that ZrPOF-Q1 as an additive can improve lubricating performance. These tribological properties make ZrPOF-Q1 a promising candidate for lubricant additive.

scholarly journals Synthesis, Tribological Properties and Mechanism of Nickel Nanoparticles as Additives in Lithium Grease

2021 ◽  
Author(s):  
Hong Zhang ◽  
wenjing hu ◽  
Jiusheng Li ◽  
sheng Han
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tribological Properties ◽  
Nickel Nanoparticles ◽  
Gravimetric Analysis ◽  
Lithium Grease ◽  
X Ray ◽  
Ft Ir ◽  
Nano Additives ◽  
Scanning Electron

Abstract The advanced nano-additives can effectively improve the tribological properties of grease, which can greatly reduce friction consumption. Therefore, we prepared nickel nanoparticles by direct reduction method using Ni(HCOO)2 • 2H2O as the basic raw material. The morphology and structure of the nanoparticles were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR spectrometer (FT-IR) and thermal gravimetric analysis (TGA). In order to investigate the lubrication performance of nickel nanoparticles in lithium grease, friction experiments were carried out on four-ball friction tester and TE77 ball-on-plate reciprocating model. Then, the worn surfaces were analyzed by scanning electron microscope and white light interferometry. Meanwhile, the element composition and valence state on friction surfaces were detected by energy dispersive spectrometer and X-ray photoelectron spectroscopy. Based on the experimental results, it was concluded that the nickel nanoparticles can effective improved the tribological properties by interlayer sliding. Moreover, the nickel nanoparticles could promote the formation of friction film on boundary lubrication surface and chemical reaction film between friction pairs. This study could provide a new direction for metal nano-additives to improve the tribological properties of grease.

Effect of thermal activation on the tribological behaviors of muscovite particles as lubricant additives in lithium grease

2018 ◽  
Vol 70 (3) ◽  
pp. 538-543 ◽  
Author(s):  
Pengfei Du ◽  
G.X. Chen ◽  
Shiyuan Song ◽  
Jiang Wu ◽  
Kechen Gu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Tribological Properties ◽  
Thermal Activation ◽  
Layer Structure ◽  
Lubricant Film ◽  
Lubricant Additives ◽  
Activation Temperature ◽  
Lithium Grease ◽  
Content Type ◽  
Worn Surface

Purpose The tribological properties of muscovite and its thermal-treated products as lubricant additives in lithium grease were investigated. The effect of thermal temperature on the crystal structure and tribological properties of muscovite was studied. This study aims to explore the tribological mechanism of muscovite and optimize a proper thermal activation temperature, thus further improving the tribological properties. Design/methodology/approach The crystal structure of muscovite samples was characterized by SEM, TG-DSC, XRD and FTIR. The tribological properties of grease samples were investigated using a four-ball tribotester and the worn surface was analyzed by SEM and EDS. Findings The excellent tribological properties of muscovite can be ascribed to the layer structure and lubricant film formed on the worn surface. Thermal temperature at 500-600°C increases the surface activity and oxygen releasing capability, and thus favors the formation of lubricant film and accordingly further improves the tribological properties. However, the layer structure is destroyed and hard phases such as alumina and amorphous appear after thermal temperature activated beyond 1000°C, as it results in the aggravation of friction and wear. Originality/value To the authors’ knowledge, it is the first to study the effect of thermal temperature on the crystal structure and tribological properties of muscovite. The tribological mechanism of muscovite particle and its thermal-treated products was disclosed.

Surface Modification of Magnesium Hydroxide with Stearic Acid

2012 ◽  
Vol 602-604 ◽  
pp. 1693-1699 ◽  
Author(s):  
Dong Sheng Zhang ◽  
Zhi Qi Liu ◽  
Li Juan Li ◽  
Li Xia Zhu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Surface Modification ◽  
Infrared Spectroscopy ◽  
Electron Microscope ◽  
Stearic Acid ◽  
Magnesium Hydroxide ◽  
Esterification Reaction ◽  
Scanning Calorimetry ◽  
Scanning Electron

The surface of magnesium hydroxide (MH) was modified with stearic acid (SA). The modification mechanism was analyzed using a scanning electron microscope, thermogravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The results showed that an esterification reaction occurred between SA and MH. The modification effect was evaluated by activation index and oil absorbance rate. The results indicated that the optimum technological conditions were as follows: SA dosage was 1.25 wt. % at 70 °C for 10 min at a stirring rate of 2000 rpm. As a result, both dispersion and hydrophobicity of modified MH were remarkably improved.

Effect of argon plasma surface modification on tribological behavior of biopolymers

2016 ◽  
Vol 68 (4) ◽  
pp. 508-514 ◽  
Author(s):  
Binnur Sagbas
Keyword(s):  
Surface Modification ◽  
Vitamin E ◽  
Tribological Properties ◽  
Wear Behavior ◽  
Argon Plasma ◽  
Wear Factor ◽  
Plasma Surface Modification ◽  
Content Type ◽  
Plasma Surface ◽  
Uhmwpe Wear

Purpose The aim of this study is to determine the effect of argon plasma surface modification on tribological properties of conventional ultra-high molecular weight polyethylene (UHMWPE) and vitamin E-blended UHMWPE. In previous studies, some researchers conducted a study on argon plasma surface modification of UHMWPE, but there is no study about argon plasma surface modification of VE-UHMWPE. So another objective of this paper is to compare the results for both the material groups. Design/methodology/approach UHMWPE and vitamin E-blended UHMWPE sample surfaces were modified by microwave-induced argon plasma to increase tribological properties of the materials. The modified surfaces were evaluated in terms of wettability and wear behavior. Wettability of the surfaces was determined by contact angle measurements. Wear behavior was examined by ball-on-disc wear tests under lubrication with 25 per cent bovine serum. Findings Argon plasma surface modification enhanced the wear resistance and surface wettability properties of conventional UHMWPE and VE-UHMWPE. Wear factor of argon plasma-treated samples reduced, but for VE-UHMWPE samples, this reduction was not as high as the conventional UHMWPE’s wear factor. Originality/value In previous studies, some researchers have studied on argon plasma surface modification of UHMWPE, but there is no study about argon plasma surface modification of VE-UHMWPE.

Tribological properties of nanometer Al2O3 and nanometer ZnO as additives in lithium-based grease

2018 ◽  
Vol 70 (6) ◽  
pp. 953-960 ◽  
Author(s):  
Qiang He ◽  
Zhigang Wang ◽  
Anling Li ◽  
Yachen Guo ◽  
Songfeng Liu
Keyword(s):  
Tribological Properties ◽  
Wear Scar ◽  
Composite Nanoparticles ◽  
Wear Testing ◽  
Wear Scar Diameter ◽  
Lithium Grease ◽  
Content Type ◽  
Wear And Friction ◽  
Friction Reducing ◽  
Base Grease

Purpose Nanoparticles as the grease additives play an important role in anti-wear and friction-reducing property during the mechanical operation. To improve the lubrication action of grease, the tribological behavior of lithium-based greases with single (nanometer Al2O3 or nanometer ZnO) and composite additives (Al2O3–ZnO nanoparticles) were investigated in this paper. Design/methodology/approach The morphology and microstructure of nanoparticles were characterized by means of transmission electron microscope and X-ray diffraction. Tribological properties of different nanoparticles as additives in lithium-based greases were evaluated using a universal friction and wear testing machine. In addition, the friction coefficient (COF) and wear scar diameter were analyzed. The surface morphology and element overlay of the worn steel surface were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), respectively. Findings The results show that the greases with nanometer Al2O3 or nanometer ZnO and the composite nanoparticles additives both exhibit lower COFs and wear scar diameters than those of base grease. And the grease with Al2O3–ZnO composite nanoparticles possesses much lower COF and shows much better wear resistance than greases with single additives. When the additives contents are 0.4 Wt.% Al2O3 and 0.6 Wt.% ZnO, the composite nanoparticles-based grease exhibits the lowest mean COF (0.04) and wear scar diameter (0.65 mm), which is about 160% and 28% lower than those of base grease, respectively. Originality/value The main innovative thought of this work lies in dealing with the grease using single or composite nanoparticles. And through a serial contrast experiments, the anti-wear and friction-reducing property with different nanoparticles additives in lithium grease are evaluated.

Effect of Oleic Acid Surface Modification on Dispersibility of TiO2 Nanoparticles in Transformer Oils

2013 ◽  
Vol 28 (6) ◽  
pp. 594-598 ◽  
Author(s):  
Yu-Zhen LÜ ◽  
Sheng-Nan ZHANG ◽  
Yue-Fan DU ◽  
Mu-Tian CHEN ◽  
Cheng-Rong LI
Keyword(s):  
Surface Modification ◽  
Oleic Acid ◽  
Tio2 Nanoparticles ◽  
Transformer Oils
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