Estimating Antiwear Properties of Ionic Liquids as Lubricant Additives Using a QSTR Model

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Ze Song ◽  
Tao Chen ◽  
Tingting Wang ◽  
Zhan Wang ◽  
Xinlei Gao
Keyword(s):  
Ionic Liquids ◽  
Influencing Factor ◽  
Three Dimensional ◽  
Predictive Ability ◽  
Lubricant Additives ◽  
Wear Scar Diameter ◽  
Base Oil ◽  
Hartree Fock ◽  
Antiwear Properties ◽  
Quantum Parameters

The antiwear properties of ionic liquids (ILs) as lubricant additives were studied with polyethylene glycol (PEG) used as the lubricant base oil. The quantum parameters of the ILs were calculated using a Hartree–Fock ab initio method. Correlation between the scale of the wear scar diameter and quantum parameters of the ILs was studied by multiple linear regression (MLR) analysis. A quantitative structure tribo-ability relationship (QSTR) model was built with a good fitting effect and predictive ability. The results show that the entropy of the ILs is the main descriptor affecting the antiwear performance of the lubricant system. To improve the antiwear performance of the lubricants, the entropy of the system should be decreased, reducing the system randomness and increasing the system regularity. A major influencing factor on the entropy of a system is the intra- and intermolecular hydrogen bonds present. Therefore, enhanced antiwear properties of lubricants could be achieved with a three-dimensional netlike structure of lubricant formed by hydrogen bonding.

BPNN-QSTR Models for Triazine Derivatives for Lubricant Additives

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Tingting Wang ◽  
Zhan Wang ◽  
Hao Chen ◽  
Kang Dai ◽  
Xinlei Gao
Keyword(s):  
Tribological Properties ◽  
Back Propagation ◽  
Three Dimensional ◽  
Predictive Ability ◽  
Quantitative Relationship ◽  
Molecular Structures ◽  
Lubricant Additives ◽  
Extreme Pressure ◽  
Wear Properties ◽  
Triazine Derivatives

Abstract Triazine derivatives are a kind of lubricant additives with excellent tribological properties. It is of great significance to study the quantitative relationship between their chemical structure and tribological properties. In the present study, the quantitative structure tribo-ability relationships (QSTR) between 20 triazine derivatives and their respective extreme-pressure properties as lubricant additives were analyzed by the back propagation neural network (BPNN) method. The BPNN-QSTR model had satisfactory stability and predictive ability (R2 = 0.9965, R2(LOO) = 0.9195, q2 = 0.8274). The anti-wear model also yielded good predictions (R2 = 0.9757, R2(LOO) = 0.6261, q2 = 0.8022). Two- and three-dimensional structural descriptors were used to analyze molecular structures that affected extreme-pressure and anti-wear properties. The results indicate that the three-dimensional molecular dimensions and the bonding modes of the skeleton atoms in the molecules were important factors. In addition, the effects of N, P, O, and other hetero-atoms on the tribological properties were reflected in their corresponding group types and electronic structures.

scholarly journals Tribological properties of novel palygorskite nanoplatelets used as oil-based lubricant additives

Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 332-343 ◽  
Author(s):  
Kunpeng Wang ◽  
Huaichao Wu ◽  
Hongdong Wang ◽  
Yuhong Liu ◽  
Lv Yang ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Magnesium Silicate ◽  
Treatment Method ◽  
Lubricant Additives ◽  
Wear Volume ◽  
Wear Scar Diameter ◽  
Tribochemical Reaction ◽  
Base Oil ◽  
Transmission Electron ◽  
Ball Surface

AbstractLayered palygorskite (PAL), commonly called attapulgite, is a natural inorganic clay mineral composed of magnesium silicate. In this study, an aqueous miscible organic solvent treatment method is adopted to prepare molybdenum-dotted palygorskite (Amo-PMo) nanoplatelets, which greatly improved the specific surface area of PAL and the dispersion effect in an oil-based lubricant system. Their layered structure and size were confirmed using transmission electron microscopy (TEM) and atomic force microscopy. Following a tribological test lubricated with three additives (PAL, organic molybdenum (SN-Mo), and Amo-PMo), it was found that the sample of 0.5 wt% Amo-PMo exhibited the best tribological properties with a coefficient of friction of 0.09. Moreover, the resulting wear scar diameter and wear volume of the sliding ball surface were 63% and 49.6% of those lubricated with base oil, respectively. Its excellent lubricating performance and self-repairing ability were mainly attributed to the generated MoS2 adsorbed on the contact surfaces during the tribochemical reaction, thereby effectively preventing the direct collision between asperities on sliding solid surfaces. Thus, as-prepared Amo-PMo nanoplatelets show great potential as oil-based lubricant additives, and this study enriches the existing application of PAL in industry.

Addition of low concentrations of an ionic liquid to a base oil reduces friction over multiple length scales: a combined nano- and macrotribology investigation

2016 ◽  
Vol 18 (9) ◽  
pp. 6541-6547 ◽  
Author(s):  
Hua Li ◽  
Anthony E. Somers ◽  
Patrick C. Howlett ◽  
Mark W. Rutland ◽  
Maria Forsyth ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Lubricant Additives ◽  
Length Scales ◽  
Base Oil ◽  
Model Base ◽  
Multiple Length Scales ◽  
Low Concentrations

The efficacy of ionic liquids (ILs) as lubricant additives to a model base oil has been probed at the nanoscale and macroscale as a function of IL concentration using the same materials.

scholarly journals Competitive Adsorption of Ionic Liquids Versus Friction Modifier and Anti-Wear Additive at Solid/Lubricant Interface—Speciation with Vibrational Sum Frequency Generation Spectroscopy

Lubricants ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 98
Author(s):  
Dien Ngo ◽  
Xin He ◽  
Huimin Luo ◽  
Jun Qu ◽  
Seong H. Kim
Keyword(s):  
Ionic Liquids ◽  
Competitive Adsorption ◽  
Silica Surface ◽  
Sum Frequency Generation ◽  
Lubricant Additives ◽  
Solid Base ◽  
Friction Modifier ◽  
Base Oil ◽  
Sum Frequency ◽  
Frequency Generation

A modern lubricant contains various additives with different functionalities and the interactions or reactions between these additives could induce synergistic or antagonistic effects in tribological performance. In this study, sum frequency generation (SFG) spectroscopy was used to investigate competitive adsorption of lubricant additives at a solid/base oil interface. A silica substrate was used as a model solid surface. The lubricant additives studied here included two oil-soluble ionic liquids (ILs, [N888H][DEHP] and [P8888][DEHP]), an antiwear additive (secondary ZDDP), an organic friction modifier (OFM), and a dispersant (PIBSI). Our results showed that for mixtures of ZDDP and IL in a base oil (PAO4), the silica surface is dominated by the IL molecules. In the cases of base oils containing OFM and IL, the silica/lubricant interface is dominated by OFM over [N888H][DEHP], while it is preferentially occupied by [P8888][DEHP] over OFM. The presence of PIBSI in the mixture of PAO4 and IL leads to the formation of a mixed surface layer at the silica surface with PIBSI as a major component. The SFG results in this investigation provide fundamental insights that are helpful to design the formulation of new lubricant additives of desired properties.

3D-QSAR Studies of S-DABO Derivatives as Non-nucleoside HIV-1 Reverse Transcriptase Inhibitors

2019 ◽  
Vol 16 (8) ◽  
pp. 868-881
Author(s):  
Yueping Wang ◽  
Jie Chang ◽  
Jiangyuan Wang ◽  
Peng Zhong ◽  
Yufang Zhang ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Three Dimensional ◽  
Predictive Ability ◽  
3D Qsar ◽  
Binding Mode ◽  
Quantitative Structure Activity Relationship ◽  
Field Analysis ◽  
Reverse Transcriptase Inhibitors ◽  
Qsar Studies ◽  
Hiv 1

Background: S-dihydro-alkyloxy-benzyl-oxopyrimidines (S-DABOs) as non-nucleoside reverse transcriptase inhibitors have received considerable attention during the last decade due to their high potency against HIV-1. Methods: In this study, three-dimensional quantitative structure-activity relationship (3D-QSAR) of a series of 38 S-DABO analogues developed in our lab was studied using Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA). The Docking/MMFF94s computational protocol based on the co-crystallized complex (PDB ID: 1RT2) was used to determine the most probable binding mode and to obtain reliable conformations for molecular alignment. Statistically significant CoMFA (q2=0.766 and r2=0.949) and CoMSIA (q2=0.827 and r2=0.974) models were generated using the training set of 30 compounds on the basis of hybrid docking-based and ligand-based alignment. Results: The predictive ability of CoMFA and CoMSIA models was further validated using a test set of eight compounds with predictive r2 pred values of 0.843 and 0.723, respectively. Conclusion: The information obtained from the 3D contour maps can be used in designing new SDABO derivatives with improved HIV-1 inhibitory activity.

Finite Element Analysis of Poor Distal Contact of the Femoral Component of a Cementless Hip Endoprosthesis

1993 ◽  
Vol 207 (4) ◽  
pp. 255-261 ◽  
Author(s):  
M Taylor ◽  
E W Abel
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Influencing Factor ◽  
Three Dimensional ◽  
Stress Distributions ◽  
Element Analysis ◽  
Hip Endoprosthesis ◽  
Applied Loading ◽  
Femoral Geometry ◽  
Contact Models

The difficulty of achieving good distal contact between a cementless hip endoprosthesis and the femur is well established. This finite element study investigates the effect on the stress distribution within the femur due to varying lengths of distal gap. Three-dimensional anatomical models of two different sized femurs were generated, based upon computer tomograph scans of two cadaveric specimens. A further six models were derived from each original model, with distal gaps varying from 10 to 60 mm in length. The resulting stress distributions within these were compared to the uniform contact models. The extent to which femoral geometry was an influencing factor on the stress distribution within the bone was also studied. Lack of distal contact with the prosthesis was found not to affect the proximal stress distribution within the femur, for distal gap lengths of up to 60 mm. In the region of no distal contact, the stress within the femur was at normal physiological levels associated with the applied loading and boundary conditions. The femoral geometry was found to have little influence on the stress distribution within the cortical bone. Although localized variations were noted, both femurs exhibited the same general stress distribution pattern.

scholarly journals Preparation of TiO2/Ti3C2Tx hybrid nanocomposites and their tribological properties as base oil lubricant additives

RSC Advances ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. 4312-4319 ◽  
Author(s):  
Maoquan Xue ◽  
Zhiping Wang ◽  
Feng Yuan ◽  
Xianghua Zhang ◽  
Wei Wei ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Tribological Properties ◽  
Lubricant Additives ◽  
Hybrid Nanocomposites ◽  
Phase Synthesis ◽  
Base Oil

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.

Thermo-physical and tribological characteristics of ionic liquid-based rice bran oil as green cutting fluid

2021 ◽  
pp. 135065012110461
Author(s):  
Aswani K Singh ◽  
Varun Sharma
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Coefficient Of Friction ◽  
Rice Bran ◽  
Alkyl Chain ◽  
Rice Bran Oil ◽  
Alkyl Chain Length ◽  
Cutting Fluid ◽  
Cutting Fluids ◽  
Base Oil

During machining, the cutting fluids play an essential role in cooling and lubrication. In order to reduce the friction forces, the excessive amount of the cutting fluids are generally used. This, in turn, leads to wastage of the cutting fluids which results in a serious impact on the environment, health and cost of production. Therefore, the judicious use of lubricants is the foremost concern in the manufacturing industry. In order to mitigate these drawbacks, various alternatives have been developed in the last decade. In the present paper, ionic liquids have been proved as favourable sustainable alternative additives in the base oil. The effect of alkyl chain length of ionic liquids with base oil on the thermo-physical and tribological characteristics of cutting fluids including viscosity, wettability, anticorrosion behaviour, thermal stability, and coefficient of friction have been analysed. In the present study, pyrrolidinium and hexafluoro-phosphate (PF6) have been used as cation and anion, respectively, with rice bran oil as base oil. The five different ionic liquids have been dispersed in base oil by 1.0 wt%. It has been found that longer alkyl chain length showed the favourable results as compared to the shorter one. Results indicated that ionic liquid based cutting fluid attained ample enhanced thermophysical and tribological properties as compared to the neat rice bran oil. There has been 5.08% and 4.29% improvement in viscosity and thermal conductivity for IL4 + RBO in comparison to neat RBO. In addition, the wettability, coefficient of friction, and wear volume have been reduced by 20.34%, 53.79% and 57.87% correspondingly.

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