Mechanochemistry in Lubrication
Lead Research Organisation:
Imperial College London
Department Name: Mechanical Engineering
Abstract
Improvements in lubricant technology are needed to reduce friction in machines and thus save energy and control global warming. Lubricants consist of a mineral or synthetic oil in which are dissolved up to ten or so chemical additives. The most important of these additives are friction and wear-reducing agents. These react with rubbing metal surfaces to form thin protective films that, as their names suggest, give low friction and wear. These films form only when surfaces rub together so they are often called "tribofilms".
Until recently we had very little idea of what caused tribofilms to form - was it the high temperature or pressure in rubbing contacts, or the metals becoming activated in some way by rubbing? This ignorance made it almost impossible to design additives except by trial and error or to build models their behaviour. However earlier this year it was shown conclusively that the most widely-used antiwear additive reacts in rubbing contacts because of the high shear forces present. These forces stretch the bonds in the molecules until they break, which leads to chemical reaction to form a tribofilm. This concept, of applied forces driving chemical reactions, is quite well known in modern chemistry and is called mechanochemistry. But this is the first time it has been shown indubitably to control tribofilm formation in the field of lubrication. It is very important insight since it points the way to us being able to predict how particular additive molecular structures will behave in rubbing contacts and thus design better additives to give lower friction and less wear.
The current project will explore the full significance of mechanochemistry to lubricant design and use. It will test which types of lubricant additive reaction are driven by shear forces and develop quantitative relations between reaction rate, applied shear force and temperature so as to enable modelling to proceed. It will look at a range of model antiwear additives with different but related structures to identify which bonds break to precipitate tribofilm formation - thereby enabling molecular structure to be optimised. It will also follow the reaction sequence that results from initial bond breaking to tribofilm formation by looking into rubbing contacts (with one transparent surface transparent) using chemical spectroscopy. All of this will be done in specially-designed test equipment that is able to reach the very high contact shear forces normally present in solid-solid rubbing contact conditions and that drive the chemical reactions involved.
The overall goal is to understand, for the first time and through the use of advanced experimental and modelling techniques, how lubricant additives react in rubbing contacts to form low friction and low wear films, and so to enable new and more energy-saving lubricants to be designed in future.
Until recently we had very little idea of what caused tribofilms to form - was it the high temperature or pressure in rubbing contacts, or the metals becoming activated in some way by rubbing? This ignorance made it almost impossible to design additives except by trial and error or to build models their behaviour. However earlier this year it was shown conclusively that the most widely-used antiwear additive reacts in rubbing contacts because of the high shear forces present. These forces stretch the bonds in the molecules until they break, which leads to chemical reaction to form a tribofilm. This concept, of applied forces driving chemical reactions, is quite well known in modern chemistry and is called mechanochemistry. But this is the first time it has been shown indubitably to control tribofilm formation in the field of lubrication. It is very important insight since it points the way to us being able to predict how particular additive molecular structures will behave in rubbing contacts and thus design better additives to give lower friction and less wear.
The current project will explore the full significance of mechanochemistry to lubricant design and use. It will test which types of lubricant additive reaction are driven by shear forces and develop quantitative relations between reaction rate, applied shear force and temperature so as to enable modelling to proceed. It will look at a range of model antiwear additives with different but related structures to identify which bonds break to precipitate tribofilm formation - thereby enabling molecular structure to be optimised. It will also follow the reaction sequence that results from initial bond breaking to tribofilm formation by looking into rubbing contacts (with one transparent surface transparent) using chemical spectroscopy. All of this will be done in specially-designed test equipment that is able to reach the very high contact shear forces normally present in solid-solid rubbing contact conditions and that drive the chemical reactions involved.
The overall goal is to understand, for the first time and through the use of advanced experimental and modelling techniques, how lubricant additives react in rubbing contacts to form low friction and low wear films, and so to enable new and more energy-saving lubricants to be designed in future.
Planned Impact
Economic Impact
This research will, for the first time, show at a molecular level how lubricant additives react at a in rubbing contacts to form low friction and low wear films. This will have immediate impact on the ability of lubricant and lubricant additive companies to design new and improved products. Currently new additive molecular designs and lubricant formulations are identified based largely on heritage knowledge and trial and error. The proposed research will transform this to a more scientific approach involving virtual testing prior followed by informed experiment.
The UK has a strong and successful presence in the lubricant and lubricant additive industrial sectors. There are two major UK-based lubricant producers as well as smaller ones. The lubricant additive sector in particular is very highly dependent on technical research and innovation as reflected in their spending on R&D. These companies will thus benefit directly from the proposed research as exemplified by the fact that a major additive and a major lubricant company have agreed to contribute both in cash and materials to the project.
The economic impact will, however, extend beyond lubricant-related industries. Currently there is strong legislative pressure on equipment manufacturers to improve the energy efficiency of their products. One important route to improved fuel efficiency is via liquid and grease lubricants that give reduced friction. Thus machine component and vehicle manufacturers will be beneficiaries of greater understanding of lubricant additive behaviour, improved low friction lubricants and reliable models of thin film lubrication. This benefit is exemplified by the fact that the world's leading rolling bearing company has agreed to contribute financially towards to the project.
Societal Impact
An urgent challenge in mechanical engineering is to increase the efficiency of machine components and so reduce energy consumption. At a national level this is needed to meet CO2 emission limits, to help cope with rising fuel costs and to reduce dependence on imported energy supplies. In global terms, increased machine use in countries such as China and India as these develop can only be mitigated by large increases in machine efficiency. Such efficiency increases can be achieved by reducing friction and it has been estimated that in passenger car vehicles, trucks and buses this has the future potential to reduce CO2 emissions by 3% of the world's total. In practical terms such friction reduction requires the parallel introduction of low viscosity lubricants and improved friction and wear-reducing additives. Such additives can only be developed and optimised from improved understanding of how they work and how their structure controls their performance, as will be provided by the current proposed research. Thus the proposed research will impact beneficially on the quest to reduce energy consumption and thereby control global warming.
A second very important societal issue is the control and reduction of NOx and particulate emissions, in particular from transport vehicles and especially in urban environments. The EU has strong legislation in place to ensure such reductions but current limits are constrained by the effectiveness of vehicle after-treatment systems. One problem is that these are susceptible to contaminants from lubricating oils, especially from the breakdown of antiwear and friction modifier additives that enter the exhaust gas via the combustion chamber. There is currently great interest in developing less harmful antiwear and friction-reducing additives. By providing understanding of the relationship between additive molecular structure and performance the proposed project should greatly assist in this quest; in particular by suggesting new molecules "outside the box" of existing lubricant additive structures rather than relying, as at present, on incremental progress based on existing experience.
This research will, for the first time, show at a molecular level how lubricant additives react at a in rubbing contacts to form low friction and low wear films. This will have immediate impact on the ability of lubricant and lubricant additive companies to design new and improved products. Currently new additive molecular designs and lubricant formulations are identified based largely on heritage knowledge and trial and error. The proposed research will transform this to a more scientific approach involving virtual testing prior followed by informed experiment.
The UK has a strong and successful presence in the lubricant and lubricant additive industrial sectors. There are two major UK-based lubricant producers as well as smaller ones. The lubricant additive sector in particular is very highly dependent on technical research and innovation as reflected in their spending on R&D. These companies will thus benefit directly from the proposed research as exemplified by the fact that a major additive and a major lubricant company have agreed to contribute both in cash and materials to the project.
The economic impact will, however, extend beyond lubricant-related industries. Currently there is strong legislative pressure on equipment manufacturers to improve the energy efficiency of their products. One important route to improved fuel efficiency is via liquid and grease lubricants that give reduced friction. Thus machine component and vehicle manufacturers will be beneficiaries of greater understanding of lubricant additive behaviour, improved low friction lubricants and reliable models of thin film lubrication. This benefit is exemplified by the fact that the world's leading rolling bearing company has agreed to contribute financially towards to the project.
Societal Impact
An urgent challenge in mechanical engineering is to increase the efficiency of machine components and so reduce energy consumption. At a national level this is needed to meet CO2 emission limits, to help cope with rising fuel costs and to reduce dependence on imported energy supplies. In global terms, increased machine use in countries such as China and India as these develop can only be mitigated by large increases in machine efficiency. Such efficiency increases can be achieved by reducing friction and it has been estimated that in passenger car vehicles, trucks and buses this has the future potential to reduce CO2 emissions by 3% of the world's total. In practical terms such friction reduction requires the parallel introduction of low viscosity lubricants and improved friction and wear-reducing additives. Such additives can only be developed and optimised from improved understanding of how they work and how their structure controls their performance, as will be provided by the current proposed research. Thus the proposed research will impact beneficially on the quest to reduce energy consumption and thereby control global warming.
A second very important societal issue is the control and reduction of NOx and particulate emissions, in particular from transport vehicles and especially in urban environments. The EU has strong legislation in place to ensure such reductions but current limits are constrained by the effectiveness of vehicle after-treatment systems. One problem is that these are susceptible to contaminants from lubricating oils, especially from the breakdown of antiwear and friction modifier additives that enter the exhaust gas via the combustion chamber. There is currently great interest in developing less harmful antiwear and friction-reducing additives. By providing understanding of the relationship between additive molecular structure and performance the proposed project should greatly assist in this quest; in particular by suggesting new molecules "outside the box" of existing lubricant additive structures rather than relying, as at present, on incremental progress based on existing experience.
Organisations
- Imperial College London (Lead Research Organisation)
- PCS Instruments (Collaboration, Project Partner)
- Afton Chemical (Collaboration)
- SKF (Sweden) (Collaboration)
- Baker Hughes (Collaboration)
- Shell Global Solutions International BV (Collaboration)
- BASF (Collaboration)
- SKF Group (International) (Project Partner)
- NewMarket Corporation (United States) (Project Partner)
- Tohoku University (Project Partner)
- Shell (United Kingdom) (Project Partner)
Publications
Zhang J
(2020)
Mechanochemistry of Zinc Dialkyldithiophosphate on Steel Surfaces under Elastohydrodynamic Lubrication Conditions.
in ACS applied materials & interfaces
Bhamra J
(2023)
Atomic-scale insights into the tribochemical wear of diamond on quartz surfaces
in Applied Surface Science
Ayestarán Latorre C
(2021)
Ab initio insights into the interaction mechanisms between boron, nitrogen and oxygen doped diamond surfaces and water molecules
in Carbon
Ayestarán Latorre C
(2021)
Mechanochemistry of phosphate esters confined between sliding iron surfaces.
in Communications chemistry
Ntioudis S
(2023)
A hybrid off-lattice kinetic Monte Carlo/molecular dynamics method for amorphous thin film growth
in Computational Materials Science
Ewen J
(2018)
Advances in nonequilibrium molecular dynamics simulations of lubricants and additives
in Friction
Spikes H
(2018)
Stress-augmented thermal activation: Tribology feels the force
in Friction
Ewen JP
(2018)
Slip of Alkanes Confined between Surfactant Monolayers Adsorbed on Solid Surfaces.
in Langmuir : the ACS journal of surfaces and colloids
Gao H
(2021)
Scale-Dependent Friction-Coverage Relations and Nonlocal Dissipation in Surfactant Monolayers.
in Langmuir : the ACS journal of surfaces and colloids
Fry BM
(2020)
Adsorption of Organic Friction Modifier Additives.
in Langmuir : the ACS journal of surfaces and colloids
Description | Lubricants contain chemical additives that are included in order to form films in rubbing surfaces that reduce friction and also protect the surfaces from damage - especially wear, seizure and fatigue. Over the last few years there has been growing realisation that the chemical reactions to form these films are driven not just by temperature, as is normally the case, but also and to a large extent by the very high stresses produced when surfaces rub together. This phenomenon is known as mechanochemistry. This project has proved unambiguously for the first time that this is indeed the case and that several additives used to reduce wear are, indeed driven to form protective films by the high shear stress in contact. It has also shown what molecular characteristics of these additives are responsive to applied stress The insights and findings of this project enable the whole process of protective film formation to be modelled accurately and this, combined with modelling of molecular reactions currently being undertaken, should make it possible in future to develop new and better additives largely using computers -requiring far less expensive and time-consuming experimental synthesis and testing to be carried out. The research has also pointed us in an important new direction t0 study the impact of rubbing on mechanochemical cleavage of C-C bonds and thus formation of protective carbon films on rubbing surfaces. We have found that this occurs much more easily in an inert atmosphere (N2 or Ar) than in air and provides a wholly new interpretation of the phenomenon known as oxidative wear. This has led us on to strong current interest in the behaviour of lubricants in inert environment conditions. We have realised that this, combined with the recent availability of low cost, low mass nitrogen concentrators may be used to develop "inerted" lubricated systems and that this could potentially make an enormous contribution to sustainability. |
Exploitation Route | Our research on shear stress-driven ZDDP tribofilm formation is already being continued by ourselves and others (e.g. Prof Carpick at Penn State) and being extended to other lubricant additives. Our finding that carbon film formation by base oils is promoted in a N2 atmosphere is already leading to a revision of views on this phenomenon and its origin. It may also be applied in future by ourselves and others to help understand the role of mechanochemistry in tribo-degradation - the more rapid degradation of lubricants when rubbing is present than when it is not. |
Sectors | Aerospace Defence and Marine Chemicals Energy Transport |
Description | It has long been known that chemical reactions can be promoted by increasing temperature or by applying an electrical potential because these provide the energy required for molecules to overcome energy barriers that impede molecular reactions. However, only in the last fifteen years or so has it been recognised that mechanical forces acting directly on molecules can also accelerate and enable chemical reactions. This has produced a burgeoning new field of chemical research - now known as mechanochemistry - which is contributing to new methods of synthesis as well as understanding of many important mechanically-mediated biochemical processes. In the mid-2010s we realised that mechanochemistry was most likely to play a particularly important role in lubrication. In lubricated contacts, surfaces are rubbed together while immersed in a liquid or grease lubricant. The lubricant contains chemicals known as additives that are designed to react with the surfaces to form low friction or wear-reducing films. The stresses at the contact points of the surfaces are enormous and are most likely to promote such chemical reactions. The challenge was how to prove and quantify this. Our project, that ran from 2017 to 2021, thus aimed at confirming conclusively the impact of mechanochemistry on lubricant additive behaviour and quantifying this at a molecular level. We did this by developing and applying a novel test rig that could provide very large and well-defined mechanical forces in rolling-sliding contacts between industrially important substrates, i.e. steel and diamond-like-carbon. Using a range of additives specially synthesised for the project by Afton Chemical, this tribometer was then used to show unambiguously that shear stress is a key driver of the formation of protective tribofilms by antiwear additives and some friction modifiers. The main impacts of this have been; (i) proof of the mechanochemical origin of the tribofilm formation reactions of the various lubricant additives; (ii) correction of a previous, erroneous belief that pressure (as opposed to shear stress) was the most important driver; (iii) proven kinetic equations for additive reaction rates as a function of shear stress and temperature for use in macroscale mixed lubrication modelling (for example they are now embedded in SKF's bearing life prediction models and several universities have used them to model tribofilm formation); (iv) development of a new high pressure test rig that has now been marketed by PCS and is being used internationally by companies and academics to develop lubricant formulations to prevent scuffing and reduce friction and wear; (v) improved understanding of molecular structure-performance relationships for lubricant additives under mechanochemical conditions (for example Shell has just funded a new PhD project with us to investigate the mechanochemical response of typical antiwear additives used in electric vehicle transmission lubricants). The second phase of the study involved the development of a method of monitoring the chemical composition of tribofilms on surfaces during rubbing. A new Raman spectrometer was designed and built that could be coupled into tribometers. This was used to quantify the change in the kinetics of friction modifier film formation due to mechanochemical effects. It has also been used in a study, with BASF that resulted from this project, of the mechanochemical processes involved in ball milling. Its main impact to date is to provide a method of monitoring the chemical evolution of additive films on surfaces during rubbing, or in response to changes of conditions, and thereby consolidating our understanding of mechanochemistry and lubricant behaviour. In parallel with the above, the project also applied a range of molecular modelling tools to study the impact of mechanical forces on lubricant additives, focussing on the additive types that have also been investigated experimentally. This has revealed the impact of molecular structure on the mechanochemical processes and has largely been validated by the experimental work. The key impact of this modelling work is that it can now be used to explore new chemical structures in silico, without the need for extensive synthesis and experimental testing. This will enable the realisation of high-throughput screening and even autonomous molecular design of new additive structures with optimized performance. It also enabled the Tribology Group to develop world-leading expertise in reactive force field (ReaxFF) molecular dynamics simulations to tribology problems, which have since been applied in a range of other projects with Shell and Baker Hughes. Both RAEng Research Fellowship (Ewen) and Shell/RAEng Research Chair in Complex Engineering Interfaces (Dini), awarded in 2020 and 2022 respectively, are now exploiting the outcomes of this project. The primary intended focus of our project was to study the response of antiwear and friction-reducing lubricant additives to the forces present in rubbing contacts. However, towards the end of the project we also discovered a new and potentially very significant mechanochemical process, the formation from hydrocarbon lubricants of very thin, protective carbon films on rubbing steel surfaces. The very high stresses in rubbing contacts cleave C-C carbon bonds to form hydrocarbyl free radicals that then combine and rearrange to form carbonaceous, graphene-like films on steel surfaces. We have found that these films form and survive best in inert gas conditions, such as a nitrogen atmosphere and this has changed a general assumption of the tribology community, which is that lubricants are generally less effective in inert gas conditions. Since nitrogen gas is now readily available using lightweight membrane systems, this opens the possibility of operating some high temperature lubricated components, such as those found in hydraulics and aircraft transmissions, in an inert atmosphere, with very large potential increases in energy efficiency and useful lubricant life. We are still in the process of disseminating this concept, known as lubricant inerting and have just started a new PhD project funded by Shell to explore it further. It is important to note that this project has played a major role in enabling appreciation of the significance of mechanochemistry become embedded in the outlook of tribology professionals, both in academia and industry. During the life of this project, a community of academic tribologists specialising in mechanochemical effects has nucleated, based largely in continental Europe and the US, and this project has ensured that the UK has been powerfully represented at the resulting meetings and debates. This community has forged strong links with mechanochemical research within chemistry as a whole; for example the PI has presented and participated at American Chemical Society (ACS) meetings on mechanochemistry and co-Is also delivered keynote talks and invited based on the outputs of the research programme. Because our Tribology Group at Imperial College has particularly strong links with industry, we have played the major role in informing lubricant and additive companies (e.g. Shell, BP, ExxonMobil, Afton Chemical, Lubrizol, and Croda (now Cargill) about the importance of mechanochemistry in lubricant design and this is starting to modify their paradigms. A very important feature of this project is that by combining, almost uniquely, both experimental and chemical modelling activities it has enabled experimental validation of the modelling tools used and these tools are now being effectively transferred to industry for additive development. Based on the above, the main impact of our work to date has been to provide to the tribology community as a whole with definitive proof that the mechanical forces present in rubbing contacts drive the formation of protective chemical films - generally known as tribofilms. This has changed the mindset of both academic researchers and industries concerned with lubricant design and performance and is leading to the development of improved lubricants and lubrication practices, with consequent energy saving and reduction of emissions. |
First Year Of Impact | 2023 |
Sector | Chemicals,Transport |
Impact Types | Economic |
Description | Ball Milling Processes |
Amount | £220,000 (GBP) |
Organisation | BASF |
Sector | Private |
Country | Germany |
Start | 02/2020 |
End | 01/2021 |
Description | Controlling Friction Through Molecular Engineering |
Amount | £500,000 (GBP) |
Organisation | Royal Academy of Engineering |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 09/2020 |
End | 09/2025 |
Description | DSTL PhD Programme: Beyond Graphene: Computational Screening of 2D Materials to Eliminate Friction |
Amount | £100,000 (GBP) |
Organisation | Defence Science & Technology Laboratory (DSTL) |
Sector | Public |
Country | United Kingdom |
Start | 09/2023 |
End | 10/2027 |
Description | EPSRC iCASE 2022 training grant - iCASE studentship with Shell (voucher number 220145) |
Amount | £135,000 (GBP) |
Funding ID | 220145 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 11/2022 |
End | 11/2026 |
Description | EPSRC iCASE 2023 training grant - iCASE studentship with Shell (voucher number 230141) |
Amount | £139,871 (GBP) |
Funding ID | EP/Y528560/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2023 |
End | 10/2027 |
Description | EPSRC iCASE 2023 training grant - iCASE studentship with Shell (voucher number 230142) |
Amount | £139,871 (GBP) |
Funding ID | EP/Y528560/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2023 |
End | 10/2027 |
Description | EPSRC iCASE 2024 training grant - iCase studentship with Shell (voucher 240151) |
Amount | £140,000 (GBP) |
Funding ID | EP/Z530761/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2024 |
End | 10/2028 |
Description | INFUSE: Interface with the Future - Underpinning Science to Support the Energy transition |
Amount | £4,191,430 (GBP) |
Funding ID | EP/V038044/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 03/2021 |
End | 02/2026 |
Description | INFUSE: Interface with the Future - Underpinning Science to Support the Energy transition |
Amount | £4,191,430 (GBP) |
Funding ID | EP/V038044/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 08/2021 |
End | 08/2026 |
Description | RAEng/Shell Research Chair in Complex Engineering Interfaces |
Amount | £1,202,967 (GBP) |
Funding ID | RCSRF2122-14-143 |
Organisation | Royal Academy of Engineering |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 03/2022 |
End | 03/2027 |
Description | iCase with Shell - An advanced modelling approach for investigating the micromechanisms of failure of flexible composite pipes under compression |
Amount | £120,000 (GBP) |
Funding ID | 19000167 (voucher) |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 08/2020 |
End | 09/2024 |
Title | Atmophere-controlled HFRR |
Description | A new research tool to investigate lubricity and wear resistance of lubricants in controlled atmosphere, i.e. inert gas such as nitrogen and argon, controlled oxygen level... |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | Due to mechanochemical reaction of base oil at asperity contacts, a carbon-based boundary film can form on rubbing surfaces to generate low friction and wear. This film is either unable to form or is oxidised in higher oxygen content atmospheres, and thus leads to high friction and wear. |
Title | Extreme traction machine |
Description | A very high pressure machine to measure fluid friction at very high pressure and to study lubricant behaviour at up to 7 GPa was commissioned and has been validated |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2018 |
Provided To Others? | Yes |
Impact | EHD traction data at < 3 GPa needed for predicting performance of rolling bearings and traction drives. Demonstration that stress derived antiwear additive reaction in steel/steel contacts |
Title | HPR |
Description | Sealed version of HFR (high frequency reciprocating rig) |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2024 |
Provided To Others? | Yes |
Impact | Study of friction and wear of ammonia gas. Direct relevance to use of ammonia as combustion fuel Shows that gs phase lubricity additives can be used to improve liubricity of hydrogen gas fuel |
Title | In-lubro MTM Raman |
Description | A new research tool to directly interrogate the chemical composition of the tribofilm on a rubbed surface formed and immersed in lubricant |
Type Of Material | Improvements to research infrastructure |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | Elcidation of the kinetics of MoDTC film formation and fricion reduction and the competing formation of carbon-based and Mo-based film material. |
Title | Data for "Mechanochemistry of Phosphate Esters Confined between Sliding Iron Surfaces" |
Description | Data from nonequilibrium Molecular Dynamics simulation of tri(n-butyl)phosphate confinid between sliding iron surfaces at 400K and 2GPa conditions, from Mechanochemistry of Phosphate Esters Confined between Sliding Iron Surfaces (10.21203/rs.3.rs-608818). Other conditions, and simulations of tri(s-butyl)phosphate simulations, are available on request. The data contains the reaxff bonding information from reaxff (bonds_*.txt), the trajectories (dump_*.lammpstrj) and the vertical and horizontal forces on the wall (fc_ave.dump), from which the shear and friction are calculated. |
Type Of Material | Database/Collection of data |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | This database is now been used as a reference by many researchers around the world and our team |
URL | https://zenodo.org/record/5708425 |
Description | Baker Hughes - PhD project |
Organisation | Baker Hughes |
Country | United States |
Sector | Private |
PI Contribution | Using molecular simulations to improve understanding of diamond-rock friction, wear, and mechanochemistry |
Collaborator Contribution | PhD funding and tribometer experiments on rock surfaces |
Impact | Collaborative paper on diamond-rock friction: https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.1c02857 |
Start Year | 2019 |
Description | Ball Milling Processes |
Organisation | BASF |
Department | Advanced Materials and Systems Research |
Country | Germany |
Sector | Private |
PI Contribution | Experimental study of mechanochemistry related to ball milling. |
Collaborator Contribution | Funding for PDRA and samples |
Impact | Report submitted to BASF. Multi-disciplinary including chemistry, mechanical engineering and materials |
Start Year | 2020 |
Description | PCS instruments - support for mechanochemistry |
Organisation | PCS Instruments |
Country | United Kingdom |
Sector | Private |
PI Contribution | We have commissioned and used a new test rig that PCS developed to our request |
Collaborator Contribution | Design , manufacture and free y of new test rig to our request Provision of a novel test rig able to operate in controlled atmosphere |
Impact | New research on tribology presented at six international conferences |
Start Year | 2017 |
Description | SKF - support for mechanochemistry |
Organisation | SKF |
Department | S.K.F. Engineering & Research Services B.V |
Country | Netherlands |
Sector | Private |
PI Contribution | Research on mechanochemstry |
Collaborator Contribution | £20000 cash plus use of SKF test equipment |
Impact | Presentations at 6 international conferences |
Start Year | 2017 |
Description | Shell Global Solutions UK Renewal |
Organisation | Shell Global Solutions International BV |
Department | Shell Global Solutions UK |
Country | Netherlands |
Sector | Private |
PI Contribution | Renewal of Shell GS UTC in Fuels and Lubricants at Imperial College 2013 |
Collaborator Contribution | Renewal of Shell GS UTC in Fuels and Lubricants at Imperial College 2018 |
Impact | Establishment of Shell GS UTC in Fuels and Lubricants at Imperial College 2013, seven PhD projects and five PDRA projects Renewal in 2108 for a further four years - four PhD students and one PDRA project to date |
Start Year | 2017 |
Description | afton chemicals- support for mechanochemistry |
Organisation | Afton Chemical |
Country | United States |
Sector | Private |
PI Contribution | We are carrying out research on new chemicals that Afton have synthesised to our request |
Collaborator Contribution | Afton Chemicals have synthesised new molecules to our design to help us understand structure-property relations of lubricant additives at a fundamental level |
Impact | Presentations and posters at five international conferences |
Start Year | 2017 |
Description | Exhibit at the Great Exhibition Road Festival - Imperial College June 2023 |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | Partecipated in activities for this large engagement event with members of the team |
Year(s) Of Engagement Activity | 2022,2023,2024 |
URL | https://www.greatexhibitionroadfestival.co.uk/ |
Description | Exhibition at the New Scientist Live, London October 2022 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | Our group routinely has an exhibition stand (E22 in 2022) at the New Scientist Live, where we explain the wonder of friction and interfaces to the general public. |
Year(s) Of Engagement Activity | 2018,2019,2022 |
URL | https://live.newscientist.com/partners-exhibitors |
Description | ITC_20190918 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | Multiple presentation in one of the largest tribology conference, showcasing our research to both practioners, students and researchers. All presentations drew large crowds and lively discussions follows |
Year(s) Of Engagement Activity | 2019 |
Description | Invited Mechanochemistry talk at RCS Chemical Challenges in Tribology symposium |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Study participants or study members |
Results and Impact | Talk to symposium on new developments in Tribology research organised by RCS - caused strong interest |
Year(s) Of Engagement Activity | 2017 |
Description | Invited talk on lubricant additives ACS Annual Fall Meeting San Francisco Aig 2023 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Meeting of tribologists in honour of Pro Spencer. Talk on ZDDP and mechanochemistry aroused strong discussion |
Year(s) Of Engagement Activity | 2023 |
URL | https://www.acs.org |
Description | Invited talk on lubricant inerting at TriboBr conference in Vitoria, Brasil, Nov 2023 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Industry/Business |
Results and Impact | Tribology conference in Vitoria, Brasil. International with strong representation from South America |
Year(s) Of Engagement Activity | 2023 |
URL | https://www.tribobr2023.com.br |
Description | Mechanochemical Behaviour of ZDDP, presentation to WTC 2017 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | Presentation to scientists and engineers at the 6th World Tribology Congress (WTC), Beijing, 2017 |
Year(s) Of Engagement Activity | 2017 |
Description | Mechanochemical behaviour of ZDDP lecture to STLE Annual conference |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Industry/Business |
Results and Impact | Lecture to scientists and engineers at STLE Annual Meeting, Atlanta, 2017 |
Year(s) Of Engagement Activity | 2017 |
Description | Mechanochemical film formation by ZDDP lecture at Asiatrib Conference 2018 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | Lecture to 6th Asia International Conference on Tribology, Kuching, September 2018. Described importance of mechanochemistry in determining ZDDP behaviour. |
Year(s) Of Engagement Activity | 2018 |
Description | Mechanochemistry in high shear stress, full film EHD conditions |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | Lecture at STLE conference in Minneapolis, May 2018 to mainly US but also international researchers/business attendees |
Year(s) Of Engagement Activity | 2018 |
Description | Organised Web Seminar Series on Tribology 2020 and 2021 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | Organised several webinars with world-leading experts in tribology. Streamed on YouTube to an audience in the thousands (https://www.youtube.com/channel/UCN0JlzEr-iPAcWNb2JBnwMw). Funding and support obtained from IMechE, RSC, IOP, and CECAM. |
Year(s) Of Engagement Activity | 2020,2021 |
URL | https://wesstribo.com/ |
Description | Poster presentation to 2018 STLE Tribology Frontiers Conference |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | Poster presentation at 2018 STLE Tribology Frontiers Conference |
Year(s) Of Engagement Activity | 2018 |
Description | Presentation at STLE Annual Meeting May 2022 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Industry/Business |
Results and Impact | Presentation of research on mechanochemical behaviour of base oils in an inert atmosphere. Much discussion and interest of the behavour observed |
Year(s) Of Engagement Activity | 2022 |
Description | Presentation at Tribochemistry Forum, Beaune, July 2022 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | Talk on mechanochemistry in inert atmospheres to ca 100 researchers interested in tribochemistry |
Year(s) Of Engagement Activity | 2022 |
Description | STLE conference_Nashville_20190520 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Industry/Business |
Results and Impact | Multiple presentations were done in STLE meeting (one of the largest professional lubrication engineering conference). They are have attracted large crowds and smaller groups discussion were held on various topics of our research. |
Year(s) Of Engagement Activity | 2019 |
Description | Stress-augmented thermal activation - a new paradigm in Tribology |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Industry/Business |
Results and Impact | Invited lecture at New Challenges in Tribology meeting organised by IET, Birmingham March 2018 |
Year(s) Of Engagement Activity | 2018 |
URL | https://pcs-instruments.com/iet-tribology-event-success-2018/ |
Description | Talk on lubricant inerting at Nextlub conference, Dusseldorf, April 2023 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Industry/Business |
Results and Impact | First conference organised jointly by German tribology/lubricants societies. "00+ delegates attending talsk on lubricant-related topics |
Year(s) Of Engagement Activity | 2023 |
URL | https://www.nextlub.com |
Description | Talk on lubricat intering and carbon film formation at Esslingen Tribology Conference, Jan 2024 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Industry/Business |
Results and Impact | Tribology conference with at least 500 attendees |
Year(s) Of Engagement Activity | 2024 |
URL | https://www.tae.de |
Description | Talk on mechanochemical carbon film formation at 24th Wear of Materials conference |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Presented new research showing for the first time that when surfaces are rubbed together in a hydrocarbon-based lubricant in a nitrogen atmosphere, a friction and wear-reducing carbon film is formed on the surfaces very rapidly by a mechanochemical process. This overturns a long-held (90 year old) model of lubricated oxidational wear and opens the possibility, coupled with nitrogen filters, of operating high temperature lubricated components such as aircraft transmissions in nitrogen gas rather than air. |
Year(s) Of Engagement Activity | 2021 |
URL | https://www.wearofmaterialsconference.com |