Lubrication at the nanoscale, soft matter at interfaces, experimental physics
Lead Research Organisation:
Durham University
Department Name: Physics
Abstract
The goal of the PhD is to investigate the dynamic surface behavior of model and real lubricants under shear at the molecular level. Using a cutting-edge approach based on atomic force microscopy operated as a linear rheometer, quantitative viscoelasticity measurements can be conducted over a small number of lubricant molecules, locally and in a controlled manner. When complemented with high-resolution images, this approach enables a comprehensive understanding of the molecular-level dynamics underpinning the lubrication properties of a given liquid confined between solids. To date, this 'bottom-up' understanding of lubrication rheology is still in its infancy. The main objective of this PhD is to derive such an understanding of selected relevant industrial systems mimicking engine surfaces by exploiting this novel approach. Ultimately, the goal is to exploit the gained insights in order to explain their performance.
Four main sections are planned. The first section will set a reference and explore the role of the main experimental parameters (other than the liquid) so as to set a reference and establish the most relevant choice of system for the study. The second section will base itself on the results on the first sections to test the properties of different liquids and additives relevant to the industrial partner (BP). The third section will investigate the effect of pressure on the measured behaviour of the confined liquid. Finally, a last section will explore how results acquired in idealized systems (sections 1-3) deviate when measurements are conducted in systems closer to the reality of working lubrication surfaces.
Four main sections are planned. The first section will set a reference and explore the role of the main experimental parameters (other than the liquid) so as to set a reference and establish the most relevant choice of system for the study. The second section will base itself on the results on the first sections to test the properties of different liquids and additives relevant to the industrial partner (BP). The third section will investigate the effect of pressure on the measured behaviour of the confined liquid. Finally, a last section will explore how results acquired in idealized systems (sections 1-3) deviate when measurements are conducted in systems closer to the reality of working lubrication surfaces.
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/P510476/1 | 01/10/2016 | 31/12/2021 | |||
| 1788302 | Studentship | EP/P510476/1 | 01/10/2016 | 30/09/2020 | Clodomiro Cafolla |
| Description | We addressed the problem of lubricated friction at the mesoscale: the impact of roughness and asperities is well characterised at the macroscale and at the atomic level, but there is still a significant gap of understanding between these two scales. We show that at the shear response of the lubricant is indirectly affected by surface defects and singularities; lubrication is dominated by the relaxation dynamics of the lubricant molecules which itself depends on the proximity of surface singularities. We also developed a non-destructive and non- invasive method to determine the torsional spring constant of a cantilever and to calculate the lateral shear force experienced by the Atomic Force Microscopy tip from the raw deflection as obtained from the photodetector. The proposed method could be particularly useful for quantitative high-resolution torsional imaging in solution and in the field of nanoscale friction and tribology, for example, when investigating ionic liquids, organic lubricants, surfactants layers, and functional nano-interfaces. |
| Exploitation Route | The results may offer a molecular-level basis for the development of tribological solutions. |
| Sectors | Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology |
| Description | My findings have helped to generate interests and foster discussions with members of the Durham Colleges community as well as with Colleagues within and outside my department. This has contributed to create great interest in the field of nanotribology as a powerful tool to address the energy problem |
| First Year Of Impact | 2017 |
| Sector | Energy,Environment |
| Impact Types | Cultural |
| Title | A non-destructive method to calibrate the torsional spring constant of atomic force microscope cantilevers in viscous environments |
| Description | we propose a calibration method that does not depend on the cantilever torsional Q-factor and show how the cantilever deflection can be converted into a lateral force. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2018 |
| Provided To Others? | Yes |
| Impact | The method could be particularly useful for quantitative high-resolution torsional imaging in solution and in the field of nanoscale friction and tribology, for example, when investigating ionic liquids, organic lubricants, surfactants layers, and functional nano-interfaces. |
| URL | https://aip.scitation.org/doi/pdf/10.1063/1.5046648?class=pdf |
| Description | Departmental and College Open days |
| 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 | Schools |
| Results and Impact | A number of about 50 prospective undergraduates and postgraduate students visited the department asking questions leading to further discussion |
| Year(s) Of Engagement Activity | 2016,2017,2018,2019 |
| Description | International Conference on Trends in Nanotribology 2017 |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | An International conference on the key topic of tribology from a nanoscale perspective. The conference fostered relationships among scientists and helped to explore new areas of research |
| Year(s) Of Engagement Activity | 2017 |
| URL | http://indico.ictp.it/event/7971/ |
| Description | Participation to the Tribology Gordon Research Conference 2018 |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | The Conference takes place every two years and brings together scientists from all around the world discussing tribological problems from a wide variety of different backgrounds |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://www.grc.org/tribology-conference/2018/ |
| Description | Research highlighted in SciLight |
| Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | After an interview with myself and other members of the research team, the journal reported some of my findings highlighting the great impact they may bring to the scientific community as well as the advantages for technological applications. |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://aip.scitation.org/doi/10.1063/1.5066415 |