Engine Oil Additives Research Articles

Lubrication antagonism mechanism of nano-MoS2 and soot particles in ester base oil

Spherical nano-MoS2 (S-MoS2) has excellent lubricating properties and potential application value in engine oil additives. Engine soot can enter the engine oil, so the tribological interaction between S-MoS2 and diesel combustion soot (DCS) should be investigated. In this study, DCS was used to simulate engine soot. The interaction was investigated in dioctyl sebacate (DOS), and the interaction mechanism was full characterized. Results showed that S-MoS2 and DCS had obvious antagonism effects on lubrication. The 0.5% S-MoS2 exhibited good lubricating properties in DOS, which could reduce friction by ∼22% and wear by ∼54%. However, after 0.5% S-MoS2 was added to the 0.5% DCS contaminated DOS, the lubrication performance was not improved and was even worse than that without S-MoS2. When S-MoS2 was added for DOS lubrication, a tribofilm containing MoS2 formed on the friction surface, but simultaneously adding 0.5% DCS resulted in the disappearance of the MoS2 tribofilm. Moreover, under the action of friction heat, DCS and S-MoS2 could form hard MoxCy, thereby increasing abrasive wear. Finally, a preliminary deantagonism method was provided. After 2.0% zinc isooctyl dithiophosphate was added to the above antagonistic system, the friction coefficient did not show visible changes, but the wear recovered to a level close to that when only S-MoS2 was added. The antiantagonism method is not very satisfactory and some more efficient methods need to be further explored.

The conjoint effect of lab-grown nano-graphene dispersant and omega-9 fatty acid surfactant on performance of CI engine

This article aims to assess the performance characteristics of lab-grown graphene nanoparticles via electrolytic exfoliation as nano additives in engine oil. Physical characterization confirmed the morphology and purity of the prepared graphene nanoparticles. Nanolubricants were prepared at 0.1%, 0.2%, and 0.3% volume fraction of the nanoparticles with the addition of oleic acid as surfactant. Measurements of density and viscosity for the nanolubricants were recorded at varying concentrations and temperatures. The performance parameters of a 4-stroke single-cylinder compression ignition (CI) engine were computed using the formulated nanolubricants. The emission of toxic gases into the environment post-engine performance evaluation was also analyzed for different formulations of nanolubricant samples. Results showed that the relative viscosity variation with concentration for the experimental data was in well agreement with other available predictive models. The nanolubricant with 0.1% concentration yielded a reduction of 13.96 ± 0.39% in total fuel consumption (TFC), a reduction of 5.55 ± 0.17% in brake-specific fuel consumption (BSFC) and an augmentation of 3.96 ± 0.13% in brake thermal efficiency (BTE) in comparison to plain engine oil and other prepared formulations. Also, a marginal reduction in emission of exhaust toxic gases i.e., (2.13 ± 0.1%) ppm in NOx and a significant maximum reduction of 7.46 ± 0.2% in smoke opacity has been obtained with 0.1% nanolubricant sample as compared to other test samples. The results from the present study may be useful for developing sustainable nanolubricants for environmental viability and energy savings.

Additives Depletion by Water Contamination and Its Influences on Engine Oil Performance

Water enters engine oil in different ways and moves in the lubrication system causing an increase in wear, oil degradation and additives depletion. It has been proposed that water in the lubricants can transfer from dissolved to free phase leading to additives depletion in the oil. Different additives in the lubricants can easily latch to water molecules forming reverse micelles. The separation of reverse micelles from the oil causes additives depletion. This experimental and analytical study aims to investigate how the separation of free water above the saturation level can diminish the efficiency of additives in engine oils. The effect of varied levels of water on oil performance and its additives was investigated in this study. A new saturation method was used to determine the water saturation level in engine oil at different temperatures. The results reveal a decrease in additive concentration with increased separation of free water from the oil. Free water separation from engine oil is expected to reclaim the tribological performance, however, the results demonstrate that tribological performance after the separation of free water from the oil has been affected. The study showed not only does the removal of free water diminish the efficiency of additives due to additives depletion (≈ 10 wt%), but also the remaining dissolved water which is ≈ 2600 ppm can also affect wear and tribofilm chemistry. The results prove that two main mechanisms influence oil performance expressed as additives depletion by free water and remaining dissolved water.

Engine Oil Degradation in the Real-World Bus Fleet Test Based on Two Consecutive Operational Intervals

The literature on the subject and the results of numerous research experiments indicate that single replacement cycles do not reflect the actual state of oil quality in the context of its degradation. Monitoring the operational quality of the oil in several successive stages allows for a more accurate diagnosis of the optimal oil change time. Therefore, it was decided to investigate the relationship between two consecutive periods of changing the operating oil in an engine. Comparative tests of seven buses included in the fleet were carried out. An important division criterion was taken into account—the operation of city and intercity buses. The HDXRF instrumental chemical analysis method was used to determine changes in the content of abrasive metals, and additives in engine oils. Additionally, the oxidation, nitration, sulfonation, and soot content were assessed using infrared spectroscopy (FTIR) based on the ASTM E2414-10 standard and kinematic viscosity at 40 °C and 100 °C using a Stabinger viscometer according to ASTM D7042. The course of these changes was analyzed in terms of their dynamics. The comparative study aimed to identify trends and sources of differences between the tested oils, as well as to demonstrate the number of exceedances of limit values for the selected parameters.

Dispersion of novel 0D carbons in 15W40 engine oil using ultrasonication for enhanced lubrication

Carbon nanomaterials have been excellent additives in lubricants to considerably enhance their lubricity. In this work, we demonstrate carbonaceous tyre pyrolysis waste (TPW) (derived from a hazardous landfilling waste material) and onion-like carbon (OLC) particles as lubricant additives in 15W40 engine oil, a well-known commercial oil (CO). Using a sustainable method, TPW was converted into high-purity (99.9 %) OLC particles at a kg scale. Different concentrations of TPW and OLC particles are dispersed in the CO using ultrasonication, and the lubricity of the additives-dispersed CO samples was assessed as per ASTM D 4172 standard. Adding TPW and OLC particles in varying concentrations into the CO lowered the viscosity and internal fluid shear stress. Tribological tests showed that the coefficient of friction (CoF) was improved by 15.9 % and 17.33 % when 0.1wt.% of TPW and OLC particles were dispersed in CO, respectively. The spherical morphology of TPW and OLC particles is beneficial in generating a nano-rolling effect at the interface of the test specimens, leading to lower CoF and wear. However, the OLC particles do not prove effective in improving the wear resistance ability of the CO, but TPW in low concentrations in CO is useful in curtailing friction and wear significantly.

Novel top-down kg-scale processing of 2D multi-layered graphene powder and its application as excellent lubricating additives in commercial engine oils

Multi-layered graphene (MLG) powder is prepared on a kg-scale using a novel fluid-assisted processing of exfoliated graphite. Each MLG particle is a few μm laterally and is constituted by a few graphene layers. When MLG-dispersed commercial engine oil was used as a lubricant, the tribological properties (i.e., friction and resistance to wear) of the contacting metal surfaces were significantly enhanced. The average coefficient of friction (CoF) at room temperature and 75 °C was reduced by ~25.5 % and ~ 16 %, respectively, while the wear resistance at room temperature and 75 °C was improved by ~13 % and ~ 16 %, respectively. MLG-dispersed engine oil forms a protective tribo-film adhering to the contacting metal surfaces, resulting in ultra-low interface friction. The MLG-dispersed engine oil (acting as a tribo-film) diminishes the effective direct metal-to-metal contact area, minimizing the wear.

Molecular-scale grinding of uniform small-size graphene flakes for use as lubricating oil additives

A variety of industrial preparation methods to obtain graphene from graphite have been developed, the most prominent of which are the chemical reduction of graphene oxide and intercalation-exfoliation methods. However, the low-cost, thin-layer, large-scale production of graphene with a radial dimension smaller than 1 μm (SG) remains a great challenge, which has limited the industrial development and application of small-scale graphene in areas such as textile fibers, engine oil additives, and graphene-polymer composites. We have developed a novel way to solve this problem by improved ball milling methods which form molecular-scale grinding aids between the graphite layers. This method can produce uniform, small-size (less than 1 μm) and thin-layer graphene nanosheets at a low cost, while ensuring minimal damage to the internal graphene structure. We also show that using this SG as an additive in lubricating oil not only solves the current dispersion stability of graphene, but also reduces the friction coefficient by more than 27% and wear by more than 38.8%. The SG preparation method reported is simple, low-cost, and has a significant effect in lubricating applications, which is of great commercial value.

Molecular dynamics simulation on engine oil nanolubricant boundary lubrication conditions

AbstractThe employment of nanoparticle additives in engine oil provides an effective technique for improvement in engine performance and emission. In this study, graphene, graphene–MWCNT, and graphene–SiO2 hybrid nanoparticles have been dispersed in engine oil (n‐decane) to measure the effects of microscopic characteristics of interfacial layer between the carbon–carbon, carbon–hydrogen, carbon–oxygen, and hydrogen–oxygen molecules under fixed shear rate 600 s−1. The boundary lubrication conditions are depicted with nanoindentation operation, in which interaction between the atoms generates the molecular forces under indentation and scratching operation that provide the nucleation and propagation of dislocation in the planes. The result shows that in an early stage of nanoindentation, plastic deformation occurs in the lubricant substrate around the indenter. Furthermore, forces generated in the z‐direction have a significant effect as compared with the forces x‐ and y‐directions. Nanoindentation results concluded that for graphene–MWCNT/engine oil (n‐decane) nanoparticles, at a volume fraction of 1.8%, the nanoparticles outperformed all other nanolubricants. At a volume fraction of 0.3%, the adhesion between the solid and liquid interface was increased by 2.5% graphene nanolubricant, 4% graphene–MWCNT nanolubricant, and 8% graphene–SiO2 nanolubricant. At 1.8% volume fraction, 240% increase in graphene–MWCNT nanolubricant, 72% increase in graphene nanolubricant, and 20% increase in graphene–SiO2 nanolubricant. This trend indicates that the performance of graphene SiO2 nanolubricants is superior at low‐volume fractions, whereas the performance of graphene nanolubricants and graphene–MWCNT nanolubricants is superior at high‐volume fractions. Also we observed the scratching effect of indenter on nanolubricants.

TiO2 Nanoparticles Coated with Nitrogen-Doped Amorphous Carbon as Lubricant Additives in Engine Oil

TiO₂ Nanoparticles Coated with Nitrogen-Doped Amorphous Carbon as Lubricant Additives in Engine Oil

PENCEMARAN KUALITAS OLI ENGINE EXCAVATOR ALAT BERAT KELAS SEBELAS TON AKIBAT KEAUSAN KOMPONEN

In this study, the focus is on the analysis of oil quality pollution caused by the thirst of the components in the engine. [7]Komponen bagian dalam engine yang dialiri oleh pelumas sangat berpotensi terjadinya kehausan yang diakibatkan oleh pergesekkan antara material yang beroperasi dalam sistem kerja engine. Oil in the engine has specifications or properties that will affect engine performance. In this study, the authors took samples on the diesel engine oil multi grade S.A.E 15W-40 which was applied to an excavator heavy equipment engine with a capacity of eleven tons. One type of Additives in engine oil is Anti-Wear which functions to reduce wear by coating the surface with an oil film. The focus of this research will be to see how much thirst occurs in the internal components of the engine that are flowing with oil. The thirst of components in the engine will be seen from the quality of the engine oil, if the thirst that occurs is greater then the work of anti-wear additives in the oil has begun to decrease so there must be a solution or analysis obtained. Test results on tests from the S.O.S. laboratory From the six sampling times, the highest wear metal value was 35 ppm at the time of operation of the 1665 Meter [Hr] unit. Based on the results of the test, it is stated that the excavator engine is in good condition when viewed from the wear metal, oil contaminant, oil condition and oil viscosity.

Performance evaluation of asphalt binders modified with waste engine oil and various additives

ABSTRACT Annually tons of waste engine oil is wasted or dumped in environmentally unfriendly ways. Asphalt binder has been modified with waste engine oil previously and showed, lower consistency, lower moisture damage resistance at higher dosages, and impaired high-temperature performance. In the current study, three different additives were added to solve these issues associated with waste engine oil-modified bitumen. Elvaloy, polyphosphoric acid (PPA), and hydrated lime (H-L) were used as polymer, chemical, and filler-type additives. Waste engine oil-modified bitumen combined with all three types of additives was evaluated using conventional viscosity, moisture susceptibility, dynamic mechanical, and chemical testing. Results showed that waste engine oil inclusion decreased the consistency of binder, reduced viscosity, and impaired high-temperature performance. Elvaloy’s addition to waste engine oil-modified bitumen made it less sensitive to temperature changes, increased the performance grade, improved the stiffness, and enhanced the resistance against rutting and moisture-induced damages. Polyphosphoric acid addition refined the consistency of binder modified with waste engine oil. It drastically increased the complex modulus values and decreased phase angle values by stiffening the binder. PPA enhanced the moisture susceptibility of asphalt and improved its high-temperature performance. Hydrated lime improved moisture resistance and bonding strength but showed less effectiveness in improving high-temperature performance at lower dosages. The results conclude that binder modification with waste engine oil can be effective with other additives like polyphosphoric acid, Elvaloy, and hydrated lime.

Complex Impact of Multifunctional Additives on Operational Parameters of Engine Oils

The powertrain is the most important and commonly the most expensive component of a vehicle. The useful life of machinery is normally determined by the operating lives of its powertrain and engine. Therefore, there are high requirements for power train reliability and longevity. This article considers the key engine reliability improvement methods, as well as the key modern development concepts for the internal combustion engine. Based on those, the authors justify the use of organic-synthesis multifunctional compounds as engine oil additives. To get a comprehensive assessment of the impacts of additives on the performance properties of engine oils, the authors developed a testing program. They described the tribological tests performed to determine the anti-corrosion properties, ash content, environmental parameters, and thermal oxidation stability. The article presents the results of these tests reflecting the efficiency of the developed additive. The article is summed up with conclusions.

Tribological analysis of advanced microwave synthesized Molybdenum disulfide (MoS2) as anti-friction additives in diesel engine oil for military vehicles

One of the most important method to reduce friction and wear is lubrication which is important in the automotive industry for energy efficiency, environmental conservation, and carbon reduction. Additionally, incorporating nanoparticles into engine oil lubricants can significantly increase their performance, particularly in terms of tribological properties. Advanced microwave synthesized Molybdenum disulfide (MoS2) anti-friction additive in SAE 20 W50 diesel engine oil was employed to formulate the nanolubricant. Fourier-transform infrared spectroscopy (FTIR) and a physical stability observation test was used to study the nano additives' physicochemical qualities (MoS2). The tribological performance of the MoS2 nanolubricant was measured using the four-ball tribotester. The Coefficient of Friction (COF) and average Wear Scar Diameter (WSD) of the anti-friction additives were analysed through tribological investigations of the wear rate and scar of the worn-out surface on ball bearings. MoS2 based nanolubricant improves COF and WSD by 10.25 % and 10.6 % respectively, as a contrast to the engine oil revealed from the tribological analysis. The current study discovered that the engine oil with advanced microwave synthesized nanoparticles have a significantly lower COF and WSD than engine oil which is not added with the anti-friction additives.

Investigation of the effect of engine oil additives on the lubricant properties of the oil by the 4-ball method

Straipsnyje nagrinėjami trintį mažinantys skirtingų gamintojų ir skirtingos sudėties alyvos priedai, taip pat naudojama kontrolinė-sintetinė alyva 5W 40. Tyrimai buvo atlikti įpilant į kontrolinę alyvą gamintojo nustatytą priedo kiekį. Pasirinkti priedai yra keturi, du priedai pagaminti molibdeno disulfido MoSo2 pagrindu. Trečias priedas yra esteris ir PAO bazinė alyva, ketvirtasis revitalizantas, pagamintas metalo keramikos pagrindu. Tribologiniams bandymams atlikti naudota modernizuota keturių rutuliukų trinties mašina MAST-1. Pirmasis bandymas buvo atliktas esant 150 N apkrovai, ir bandymo trukmei – 3600 sekundžių sukimo. Priedai buvo jau sumaišyti su kontroline alyva. Kiti bandymai buvo atlikti esant 150N ir 300N apkrovai, įpilant priedo po 3600 sekundžių, bendra bandymo trukmė 7200 sekundžių su keturių rutuliukų trinties mašina MAST-1.

Comparison of Olefin Copolymers and Comb Polymers in Engine Oil Formulations Tested for Fuel Efficiency Retention and CO <sub>2</sub> Emissions Under Advanced Emission Standards

<div class="section abstract"><div class="htmlview paragraph">This study presents the impact of two engine oil additives on fuel efficiency and CO<sub>2</sub> emissions. Formulations containing either Olefin Copolymer (OCP) or Comb polymer (Comb) were compared in tests for fuel efficiency retention, fine particle emissions, and ash accumulation in the gasoline particulate filter. The Comb formulations showed higher fuel efficiency throughout the testing, retaining this efficiency after three distinct engine aging test cycles. No significant differences between formulations were observed in oil consumption, ash accumulation, and filtration efficiency.</div></div>

Influence of Base oil Polarity on the Tribological Performance of Surface-Active Engine Oil Additives

Friction, wear and tribofilm growth of organic friction modifiers (glycerol monooleate and oleamide), anti-wear additive (ZDDP) and binary additive system comprising the organic friction modifiers and ZDDP were studied in polyalphaolefin (PAO) and ester oil. The mechanisms underlying base oil polarity-dependent frictional performance of the OFM and AW additives at high temperature (140 ℃), either singly or in combination, were investigated in the light of chemical composition analysis of the tribofilms post friction measurements using energy dispersive X-ray spectroscopy (EDX), static and dynamic time-of-flight secondary ion mass spectrometry (ToF–SIMS). Depending on the rubbing conditions, the boundary friction coefficient of the binary additive systems was found to be either lower than that of individual additives or to lay between the values for the individual additives. Chemical composition analysis of the tribofilms indicated that the nature of base oil controlled interactions between ZDDP and OFM and consequently adsorption and reactive tribofilm formation in the boundary lubrication layer. Surface roughness and wear scar width measured post tribological tests using 3D surface profiler showed improved wear performance in both PAO and ester-based additive formulations.

Chemical and physical assessment of engine oils degradation and additive depletion by soot

Soot contamination in engine oil causes a significant increase in wear of engine components. Presence of soot in the engine oil is one of the most common reasons leading to an increase in oil change intervals. There are several mechanisms that affect the performance of engine oil such as oil degradation, additive decomposition and additive adsorption on soot particles. It is recommended that removal of soot contamination from engine oil can reduce wear of engine components and extend the service life of engine oil. However, removing soot particles from the engine oil can diminish the efficiency of additives in engine oils as some additives adsorbs on these particles. There is still no census on this area. Thus, this experimental study aims to investigate how removing different levels of Carbon Black Particles (CBP), commonly used as surrogate for soot, from aged engine oil influences the engine oil performance. The study reveals three main mechanisms that influence the tribological performance of the engine oil expressed as additive depletion, additive adsorption and degradation products. Removal of CBP from engine oil is expected to reclaim the oil performance. However, the results demonstrate that the performance of oil after removal of CBP is still not as good as the fresh oil. These results confirms that reclaiming the oil performance can not be achieved by just removing the CBP. Other mechanisms such as oil degradation and additive adsorption on CBP adversely affect the engine oil performance during the removal of CBP.

Synergistic and Competitive Effects between Zinc Dialkyldithiophosphates and Modern Generation of Additives in Engine Oil

The increasing demand for low-viscosity engine oil has underscored the role of zinc dialkyldithiophosphates (ZDDP) as a conventional anti-wear and antioxidant additive. It is essential to investigate the influence of modern additives such as cyclopropanecarboxylic acid (CPCa) and Ni nanoparticles on the tribological performance of ZDDP for practical commercial oil application. According to the experimental results, Ni nanoparticles formed a protective film that exhibited a synergistic effect with ZDDP. A significantly higher concentration of sulphur in the tribofilm was detected compared to ZDDP by itself, which was responsible for a 27.6% lower wear loss. Meanwhile, a competitive effect between CPCa and ZDDP resulted in a dramatic increase in friction and unstable anti-wear performance. This was demonstrated by a localized formation of the ZDDP tribofilm on the wear surfaces after the friction test. These results have highlighted the synergistic and competitive effects of emerging additives (CPCa and Ni nanoparticles) in the ZDDP tribofilm formation between the sliding steel contacts. This further suggests a new approach to increase the efficiency of ZDDP’s tribological performance at cold start-up processes.

Hybrid Nanocellulose-Copper (II) Oxide as Engine Oil Additives for Tribological Behavior Improvement

Friction and wear are the main factors in the failure of the piston in automobile engines. The objective of this work was to improve the tribological behaviour and lubricant properties using hybrid Cellulose Nanocrystal (CNC) and Copper (II) oxide nanoparticles blended with SAE 40 as a base fluid. The two-step method was used in the hybrid nanofluid preparation. Three different concentrations were prepared in a range of 0.1% to 0.5%. Kinematic viscosity and viscosity index were also identified. The friction and wear behavior were evaluated using a tribometer based on ASTM G181. The CNC-CuO nano lubricant shows a significant improvement in term of viscosity index by 44.3–47.12% while for friction, the coefficient of friction (COF) decreases by 1.5%, respectively, during high and low-speed loads (boundary regime), and 30.95% during a high-speed, and low load (mixed regime). The wear morphologies results also show that a smoother surface was obtained after using CNC-CuO nano lubricant compared to SAE 40.

Interactions between organic friction modifier additives

The interactions of different additives in engine oils can create synergistic or antagonistic effects. This paper studies how mixing different organic friction modifier additives affects friction reducing properties of lubricants in the boundary lubrication regime. Amines of different degree of saturation were mixed with either glycerol monooleate (GMO) or oleic acid in hexadecane. The model lubricants thus formed were characterised with Fourier-transform infrared spectroscopy. Friction tests in reciprocating motion using ball-on-disc steel-steel contacts were conducted to examine the tribological performance of these lubricants. Worn surfaces were examined using X-ray photoelectron spectroscopy. Oleic acid and oleylamine, a primary amine, were found to form a partial ionic liquid, providing synergistic friction reduction. This positive interaction reduces with increasing degree of saturation of the amine. No synergistic effect was observed between GMO and oleylamine, suggesting that GMO does not hydrolyse into a carboxylic acid within a rubbing contact in the presence of amine.