Dispersion Stability And Tribological Properties of Covalently Modified Graphene As A Lubricating Oil Additive

2021 ◽  
Author(s):  
Mingyue Wang ◽  
Ming Zhou ◽  
Shengli You ◽  
Xin Chen ◽  
Youtang Mo ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Covalent Modification ◽  
Dispersion Stability ◽  
Lubricating Oil ◽  
Primary Amines ◽  
Base Oil ◽  
Amide Bonds ◽  
Stable Dispersion ◽  
Wide Range ◽  
Modified Graphene

Abstract Graphene has excellent mechanical properties with a low coefficient of friction and wear resistance and has a wide range of tribological applications. However, the stable dispersion of graphene in lubricating media is challenging. In this study, graphene is processed via covalent modification. A mild oxidation method selectively grafts carboxyl groups on the edge of the graphene sheet, before connecting tertiary alkyl primary amines through amide bonds. The alkyl chain allows graphene to be stably dispersed in hydrocarbon solvents.. FT-IR, XPS, Raman, XRD, SEM, etc. are used to characterize the covalently modified graphene (MG). Dispersion stability experiments showed that MG exhibited stable dispersion in 500N base oil and 15w-40 commercial lubricants, with stability for over 2 months. Tribological test results show that MG in 500N and 15w-40 significantly reduces the friction and wear of steel-steel friction pairs. The stable dispersion of MG in lubricating oil enables the formation of a stable chemical reaction film and graphene physical deposition film during the friction, protects the worn surface, and reduces direct contact, thereby significantly reducing friction and wear.

scholarly journals Modified graphene as novel lubricating additive with high dispersion stability in oil

Friction ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Pu Wu ◽  
Xinchun Chen ◽  
Chenhui Zhang ◽  
Jiping Zhang ◽  
Jianbin Luo ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Wear Track ◽  
Normal Load ◽  
Lubricant Additive ◽  
Tribological Performance ◽  
Dispersion Stability ◽  
High Dispersion ◽  
Base Oil ◽  
The Coefficient Of Friction ◽  
Modified Graphene

Abstract Graphene is a promising material as a lubricant additive for reducing friction and wear. Here, a dispersing method which combines chemical modification of graphene by octadecylamine and dicyclohexylcarbodiimide with a kind of effective dispersant has been successfully developed to achieve the remarkable dispersion stability of graphene in base oil. The stable dispersion time of modified graphene (0.5 wt%) with dispersant (1 wt%) in PAO-6 could be up to about 120 days, which was the longest time reported so far. At the same time, the lubricant exhibits a significant improvement of tribological performance for a steel ball to plate tribo-system with a normal load of 2 N. The coefficient of friction between sliding surfaces was ~0.10 and the depth of wear track on plate was ~21 nm, which decreased by about 44% and 90% when compared to pure PAO-6, respectively. Furthermore, the analysis of the lubricating mechanisms in regard to the sliding-induced formation of nanostructured tribo-film has been contacted by using Raman spectra and TEM.

scholarly journals Tribological properties of synthetic base oil containing polyhedral oligomeric silsesquioxane grafted graphene oxide

RSC Advances ◽  
2018 ◽  
Vol 8 (42) ◽  
pp. 23606-23614 ◽  
Author(s):  
Bo Yu ◽  
Kai Wang ◽  
Yiwen Hu ◽  
Feng Nan ◽  
Jibin Pu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Lubricating Oil ◽  
Wear Performance ◽  
Base Oil ◽  
Oligomeric Silsesquioxane

The dispersion of graphene-based materials in lubricating oil is a prerequisite for improving its friction and wear performance.

Study on tribological properties of nano lubricating oil blends for diesel engines

Nano Futures ◽  
2021 ◽  
Author(s):  
Xin Kuang ◽  
Bifeng Yin ◽  
Xiping Yang ◽  
Hekun Jia ◽  
Bo Xu
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Tribological Properties ◽  
Diesel Engines ◽  
Dispersion Stability ◽  
Lubricating Oil ◽  
Oil Blends ◽  
Before And After ◽  
Nano Graphene ◽  
Modified Graphene

Abstract This paper is to evaluate and compare the tribological properties of lubricating oil blends added with nano graphene and lubricating oil blends added with cerium oxide (CeO2) on the key friction pairs of the diesel engines. The dispersion stability is the premise of studying the tribological properties. In this paper, nano-CeO2 particles were self-made and high-quality nano-graphene was purchased. The dispersion stability of the two nanomaterials in lubricating oil was studied after the same modification respectively. According to the working conditions of the cylinder liner and the piston ring, the friction and wear tests of the lubricating oil blends added with the modified nanomaterials were carried out at the different temperatures. The results showed that the oleic acid and the stearic acid modified the two nanomaterials successfully. The dispersion stability of the modified nanomaterials in lubricating oil was improved. The dispersion stability of the lubricating oil blends added with graphene before and after modification was slightly higher than that of lubricating oil blends added with CeO2 before and after modification, respectively. At the high temperature, the anti-friction property of the two nano lubricating oil blends was similar. At the ambient temperature, lubricating oil blends added with modified CeO2 did not play a role in reducing friction, while lubricating oil blends added with modified graphene had the effect of reducing friction. Whether at ambient temperature or at the high temperature, the anti-wear property lubricated with lubricating oil blends added with modified CeO2 within the right concentration range was better than that lubricated with lubricating oil blends added with modified graphene.

scholarly journals Effect of Temperature and Surface Roughness on the Tribological Behavior of Electric Motor Greases for Hybrid Bearing Materials

Lubricants ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 59
Author(s):  
Daniel Sanchez Garrido ◽  
Samuel Leventini ◽  
Ashlie Martini
Keyword(s):  
Surface Roughness ◽  
Friction And Wear ◽  
Tribological Behavior ◽  
Effect Of Temperature ◽  
Base Oil ◽  
Future Studies ◽  
Lubrication Regimes ◽  
Wide Range ◽  
Bearing Materials ◽  
Hybrid Bearing

Greased bearings in electric motors (EMs) are subject to a wide range of operational requirements and corresponding micro-environments. Consequently, greases must function effectively in these conditions. Here, the tribological performance of four market-available EM greases was characterized by measuring friction and wear of silicon nitride sliding on hardened 52100 steel. The EM greases evaluated had similar viscosity grades but different combinations of polyurea or lithium thickener with mineral or synthetic base oil. Measurements were performed at a range of temperature and surface roughness conditions to capture behavior in multiple lubrication regimes. Results enabled direct comparison of market-available products across different application-relevant metrics, and the analysis methods developed can be used as a baseline for future studies of EM grease performance.

scholarly journals Tribological performance of nano-diamond composites-dispersed lubricants on commercial cylinder liner mating with CrN piston ring

2020 ◽  
Vol 9 (1) ◽  
pp. 455-464
Author(s):  
Ruoxuan Huang ◽  
Zichun Wang ◽  
Xiaoshuai Yuan ◽  
Tianchi Zhang ◽  
Siqi Ma ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Friction And Wear ◽  
Piston Ring ◽  
Negative Impact ◽  
Friction Pair ◽  
Cylinder Liner ◽  
Lubricating Oil ◽  
Wear Loss ◽  
Base Oil ◽  
Cylinder Liners

AbstractThis work investigated the effect of nanodiamond (ND) additives on the tribological properties of CrN-coated piston ring mating with the chromium-plated and BP alloy iron cylinder liners, which is one of the key friction pairs in the internal combustion engines. To enhance the dispersion of the NDs in the base oil, the surface of ND particles was modified with polyaniline via in situ polymerization. The friction and wear as well as the scuffing characteristics of the friction pair lubricated with different contents of ND composite-added base oil were evaluated by using the reciprocating tribotests, which are close to the actual conditions. The wear surface morphologies and elements distribution were analyzed to explore the wear behaviors and the associated mechanisms of friction pairs under the lubrication incorporated with the ND composites. The results show that the ND additive is beneficial for the pair of Cr liner and CrN-coated piston ring in the friction and wear as well as scuffing properties, and the best concentration of ND additive is expected to be around 1 wt%. But for the BP liner, the developed nanocomposite has a negative impact. The friction force and the wear loss of the pair lubricated by the ND composite-added oil are even worse than that tested with the base lubricating oil.

scholarly journals A New Method for Dispersing Pristine Carbon Nanotubes Using Regularly Arranged S-Layer Proteins

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1346
Author(s):  
Andreas Breitwieser ◽  
Uwe B. Sleytr ◽  
Dietmar Pum
Keyword(s):  
Carbon Nanotubes ◽  
Covalent Modification ◽  
Silica Layer ◽  
Medical Sciences ◽  
Lysinibacillus Sphaericus ◽  
Wide Range ◽  
Catalytic Sites ◽  
Multi Walled Carbon Nanotubes ◽  
Pristine Mwnts ◽  
Walled Carbon Nanotubes

Homogeneous and stable dispersions of functionalized carbon nanotubes (CNTs) in aqueous solutions are imperative for a wide range of applications, especially in life and medical sciences. Various covalent and non-covalent approaches were published to separate the bundles into individual tubes. In this context, this work demonstrates the non-covalent modification and dispersion of pristine multi-walled carbon nanotubes (MWNTs) using two S-layer proteins, namely, SbpA from Lysinibacillus sphaericus CCM2177 and SbsB from Geobacillus stearothermophilus PV72/p2. Both the S-layer proteins coated the MWNTs completely. Furthermore, it was shown that SbpA can form caps at the ends of MWNTs. Reassembly experiments involving a mixture of both S-layer proteins in the same solution showed that the MWNTs were primarily coated with SbsB, whereas SbpA formed self-assembled layers. The dispersibility of the pristine nanotubes coated with SbpA was determined by zeta potential measurements (−24.4 +/− 0.6 mV, pH = 7). Finally, the SbpA-coated MWNTs were silicified with tetramethoxysilane (TMOS) using a mild biogenic approach. As expected, the thickness of the silica layer could be controlled by the reaction time and was 6.3 +/− 1.25 nm after 5 min and 25.0 +/− 5.9 nm after 15 min. Since S-layer proteins have already demonstrated their capability to bind (bio)molecules in dense packing or to act as catalytic sites in biomineralization processes, the successful coating of pristine MWNTs has great potential in the development of new materials, such as biosensor architectures.

scholarly journals Friction and Wear Behavior of Polyamide 66 Composites Filled with Rice Bran Ceramics under a Wide Range of Pv Values

2015 ◽  
Vol 10 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Kei Shibata ◽  
Takeshi Yamaguchi ◽  
Moeko Kishi ◽  
Kazuo Hokkirigawa
Keyword(s):  
Rice Bran ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Polyamide 66 ◽  
Friction And Wear Behavior ◽  
Wide Range

scholarly journals Regeneration of Spent Lubricant Refining Clays by Solvent Extraction

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yan-zhen Wang ◽  
Hai-long Xu ◽  
Li Gao ◽  
Meng-meng Yan ◽  
Hong-ling Duan ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Petroleum Ether ◽  
Oil Recovery ◽  
Oil Refining ◽  
Lubricating Oil ◽  
Polar Solvents ◽  
Base Oil ◽  
Nonpolar Solvents ◽  
Total Oil ◽  
Storage Times

Step-by-step solvent extraction was used to regenerate spent clay by recovering the adsorbed oil in lubricating oil refining clay. Several polar and nonpolar solvents were tested, and petroleum ether (90–120°C) and ethanol (95 v%) were selected as the nonpolar and polar solvents, respectively. The spent clay was first extracted using petroleum ether (90–120°C) to obtain ideal oil and then extracted with a mixed solvent of petroleum ether (90–120°C) and ethanol (95 v%) two or three times to obtain nonideal oil before being extracted with ethanol and water. Finally, the clay was dried at 130°C to obtain regenerated clay. The total oil recovery can be more than 99 wt% of the adsorbed oil. The recovered ideal oil can be used as lubricating base oil. Shorter storage times for spent clay produce better regeneration results. The regenerated clay can be reused to refine the lubricating base oils.

Tribological Properties of Zirconium Oxide, Spinel and Mullite Nanopowders as Lubricating Oil Additives

2016 ◽  
Vol 721 ◽  
pp. 451-455
Author(s):  
Armands Leitans ◽  
Eriks Palcevskis
Keyword(s):  
Tribological Properties ◽  
Zirconium Oxide ◽  
Friction Pair ◽  
Synthesis Method ◽  
Lubricating Oil ◽  
Nanosized Powders ◽  
Base Oil ◽  
Oil Additives ◽  
Oxide Spinel ◽  
Lubricating Oil Additives

In work investigated effects of zirconium oxide (ZrO2), spinel (MgAl2O4) and mullite (Al6Si2O13) nanosized powders on the base oil tribological properties. The nanosized (30-40nm) powders manufactured by plasma chemical synthesis method. Tribological experiments used on ball-on-disc type tribometer, measured coefficient of friction and determined metalic disc wear. Base oil used selectively purified mineral oil (conform SAE-20 viscosity) without any functional additives. Nanosized powders dispersed in base oil at 0.5; 1.0; 2.0; wt.%. At work cocluded, that the adition nanoparticles in base oil, possible reduced friction pair wear and friction coefficient. As the main results include spinel (MgAl2O4) nanoparticles 0.5 and 1.0 wt. % concentration ability reduced friction coeffiecient value.

Experimental Study on the Tribological Characteristics of Nanometer WS2 Lubricating Oil Additive Based on Engine Oil

2011 ◽  
Vol 328-330 ◽  
pp. 203-208 ◽  
Author(s):  
Cheng Bin Chen ◽  
Da Heng Mao ◽  
Chen Shi ◽  
Yang Liu
Keyword(s):  
Raw Materials ◽  
Viscosity Index ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Contrast Study ◽  
Base Oil ◽  
Grinding Conditions ◽  
Lubricating Oil Additive ◽  
Great Wall ◽  
Better Than

Nano-WS2(tungsten disulfide nanoparticles)lubricating oil additive, prepared by the nanometer WS2particulates and semi-synthetic engine base oil as raw materials, was added into Great Wall engine oil with different mass ratio. With a contrast study on these oil samples, the results show that it can improve the extreme pressure, antiwear and viscosity-temperature properties of the engine oil effectively by adding a certain amount of nano-WS2additive, and the optimal concentration is 2wt%. The oil film strength, sintering load and viscosity index of this lubricating oil is respectively 1.35 times, 1.58 times and 1.05 times as that of Great Wall engine oil. In addition, when tested under the grinding conditions of 392 N, 1450 r /min and 30 min, the diameter of worn spot reduces 0.018mm, and the average friction coefficients of friction pairs decrease 16.3%, both of which are lubricated by the oil containing nano-WS2additive. Meanwhile, the experiments testify that the tribological and viscosity-temperature properties of the nano-WS2additive are better than that of the Henkel MoS2additive.

Sign in / Sign up

Export Citation Format

Share Document