Knowledge

Welcome to our knowledge centre. Here you can find a selection of resources and articles on our products and industries we are involved with.

Paper

Visualisation of Structured Lubricants in Tribological Contacts

The layered, lamellar phase of lyotropic liquid crystals display promising tribological properties possessing low shear strength between layers, solid like …

The layered, lamellar phase of lyotropic liquid crystals display promising tribological properties possessing low shear strength between layers, solid like elasticity and high load carrying capacity perpendicular to their layered structure. Being able to visualise and study the behaviour of LLC in high pressure contacts at a range of speed, slide-roll ratio (SRR) and temperature conditions can facilitate the understanding of the mechanism of action behind their low friction properties.

A microscope setup has been developed that is capable of collecting real time, high contrast videos of film formation, bulk alignment, and flow of liquid crystal containing lubricants in an EHD ultra-thin film tribometer. This project aims to describe an economic set of methods to evaluate qualitatively the behaviour of liquid crystals in and around tribological contacts.

This is demonstrated with two types of liquid crystals; lamellar lyotropic Oleic Acid/Triethanolamine and smectic thermotropic 8CB.

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Paper

Salivary Lubricity (Ex Vivo) Enhances Upon Moderate Exercise: A Pilot Study

This study sought to examine the effects of moderate intensity exercise on lubrication performance of saliva. We hypothesized that exercise …

This study sought to examine the effects of moderate intensity exercise on lubrication performance of saliva. We hypothesized that exercise would result in enhanced salivary lubricity by direct sympathetic stimulation of the salivary proteins…
In total, 11 healthy young pre-menopausal female participants (mean age: 24.4 ± 1.8 years, BMI: 22.1 ± 1.9 kg/m2) were included in a within-subjects repeated measures experimental design. Unstimulated whole saliva was collected at rest (S0), immediately after 45 min of moderate intensity cycling at ∼70 % maximum heart rate (mean: 133.4 ± 0.8 bpm) or time-match quiet rest (S1), and after a 60 min of recovery period (S2). Ex vivo salivary lubricity were measured using soft tribology. Total protein content, mucin (MUC5B) concentration, and α-amylase activity were determined.

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Paper

Composition Containing Heterocyclic Compounds And A Method Of Lubricating An Internal Combustion Engine

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected …

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

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Paper

Amino Acid Grafted Polymer with Soot Handling Properties

The present disclosure relates to lubricant additives such as dispersants and dispersant viscosity modifiers including acyl peptide grafted polymers and …

The present disclosure relates to lubricant additives such as dispersants and dispersant viscosity modifiers including acyl peptide grafted polymers and lubricating oil compositions comprising such additives. The disclosure also relates to the use of lubricant compositions comprising the additives herein for improving the soot or sludge handling characteristics of an engine lubricant composition and while minimizing the deterioration of engine's elastomer compatibility.

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Paper

Integrated Friction Reduction Technology to Improve Fuel Economy without Sacrificing Durability

This report describes the results of a study in response to the FY2014 Vehicle Technologies program DE-FOA-0000991 solicitation for fuel …

This report describes the results of a study in response to the FY2014 Vehicle Technologies program DE-FOA-0000991 solicitation for fuel economy improvement of cars and trucks (Area of interest 11: powertrain friction and wear reduction). It stated, “parasitic losses within vehicle engines and drivetrains are responsible for approximately two million barrels of oil consumption per day in the US. These losses are caused by friction between components, movement of components through fluids, and movement of fluids through components”. The objective of the study is to develop and demonstrate friction and wear reduction technologies for light duty vehicles that improve fuel efficiency of legacy vehicles by at least 2%, without adverse impacts on vehicle performance or durability.

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Paper

Friction Measurements with Molten Chocolate

A novel test is reported which allows the measurement of the friction of molten chocolate in a model tongue–palate rubbing …

A novel test is reported which allows the measurement of the friction of molten chocolate in a model tongue–palate rubbing contact. Friction was measured over a rubbing period of 150 s for a range of commercial samples with different cocoa content (85–5% w/w). Most of the friction curves had a characteristic pattern: initially a rapid increase occurs as the high-viscosity chocolate melt is sheared in the contact region followed by friction drop as the film breaks down. The exceptions were the very high (85%) and very low (~ 5%) cocoa content samples which gave fairly constant friction traces over the test time. Differences were observed in the initial maximum and final friction coefficients depending on chocolate composition. Generally, the initial maximum friction increased with increasing cocoa content. At the end of the test, the rubbed films on the lower slide were examined by optical microscopy and infrared micro-reflection spectroscopy. In the rubbed track, the chocolate structure was severely degraded and predominately composed of lipid droplets, which was confirmed by the IR spectra. The new test provides a method to distinguish between the friction behaviour of different chocolate formulations in a rubbing low-pressure contact. It also allows us to identify changes in the degraded chocolate film that can be linked to the friction profile. Further development of the test method is required to improve simulation of the tongue–palate contact including the effect of saliva and this will be the next stage of the research.

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Paper

Two Fatty Acid Anion-based Ionic Liquids – Part II: Effectiveness As An Additive To A Polyol Ester

This work is about the use of two ionic liquids obtained from fatty acids (FAILs) as an additive at 0.5 …

This work is about the use of two ionic liquids obtained from fatty acids (FAILs) as an additive at 0.5 and 2 wt% to a polyol ester (POE) base oil. Tribological tests under two different configurations (reciprocating and sliding/rolling “ball-on-disc”) were performed at different temperatures and loads. Worn surface was measured and analyzed after reciprocating experiments by confocal and scanning electron microscopies and by X-ray photoelectron spectroscopy (XPS). Main results showed that these FAILs at low concentration did not change the viscosity of the POE and hence the tribological behaviors of the mixtures and the POE under elastohydrodynamic lubrication (EHL) in rolling/sliding tests were similar, but using mixtures resulted in lower friction regarding the POE under mixed lubrication regime; the friction behavior in reciprocating tests was similar with the use of all mixtures and the POE at 25 °C for the two loads used, while the mixtures outperformed the antiwear behavior of the POE; the antifriction behavior of the mixtures under both loads at 100 °C was slightly worse than that of the POE and all mixtures had better antiwear performance than the POE.

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Paper

The Role Of MoDTC Tribochemistry In Engine Tribology Performance. A Raman Microscopy Investigation

In order to tackle the new challenges towards the reduction of carbon emissions in transport industry, the present work aims …

In order to tackle the new challenges towards the reduction of carbon emissions in transport industry, the present work aims to understand the effect of the friction modifier (FM) molybdenum dithiocarbamate (MoDTC) on the performance of an automobile engine. A petrol engine has undergone motored test trials, measuring the friction torque reduction when the FM additive is blended into a fully formulated SAE 5W30 oil. Moreover, the engine has been dismantled after the test, investigating the tribochemistry of MoDTC at different key engine components undergoing boundary lubrication, using Raman microscopy. This work demonstrates that materials and contact pressure play a crucial role in MoDTC tribochemistry to form a low friction tribofilm, contributing to global engine friction reduction.

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Paper

Exploring Mouthfeel in Model Wines: Sensory-to-Instrumental Approaches

Wine creates a group of oral-tactile stimulations not related to taste or aroma, such as astringency or fullness; better known …

Wine creates a group of oral-tactile stimulations not related to taste or aroma, such as astringency or fullness; better known as mouthfeel. During wine consumption, mouthfeel is affected by ethanol content, phenolic compounds and their interactions with the oral components. Mouthfeel arises through changes in the salivary film when wine is consumed. In order to understand the role of each wine component, eight different model wines with/without ethanol (8%), glycerol (10 g/L) and commercial tannins (1 g/L) were described using a trained panel. Descriptive analysis techniques were used to train the panel and measure the intensity of the mouthfeel attributes. Alongside, the suitability of different instrumental techniques (rheology, particle size, tribology and microstructure, using Transmission Electron Microscopy (TEM)) to measure wine mouthfeel sensation was investigated. Panelists discriminated samples based on their tactile-related components (ethanol, glycerol and tannins) at the levels found naturally in wine. Higher scores were found for all sensory attributes in the samples containing ethanol. Sensory astringency was associated mainly with the addition of tannins to the wine model and glycerol did not seem to play a discriminating role at the levels found in red wines. Visual viscosity was correlated with instrumental viscosity (R =0.815, p=0.014). Hydrodynamic diameter of saliva showed an increase in presence of tannins (almost 2.5–3-folds). However, presence of ethanol or glycerol decreased hydrodynamic diameter. These results were related with the sensory astringency and earthiness as well as with the formation of nano-complexes as observed by TEM. Rheologically, the most viscous samples were those containing glycerol or tannins. Tribology results showed that at a boundary lubrication regime, differences in traction coefficient lubrication were due by the presence of glycerol. However, no differences in traction coefficients were observed in presence/absence of tannins. It is therefore necessary to use an integrative approach that combines complementary instrumental techniques for mouthfeel perception characterization.

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