Formation of low-friction tribofilms from organic lubricant additives: mechanisms and structure-property relationships from molecular modelling

• Applicant: Dr. Stefan Peeters
• Subject Area: Computer-Aided Design of Materials and Simulation of Materials Behaviour from Atomic to Microscopic Scale ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 584208652

Due to high energy and material losses caused by frictional phenomena, it is highly desirable to optimize lubrication in moving parts. One possibility is via tribofilms, that can be formed by lubricant additives during tribological contact and protect sliding interfaces from friction and wear. It would be ideal to substitute hazardous lubricant compounds with sustainable alternatives that do not represent a threat to human health and the environment, without sacrificing their cost-effectiveness. In this context, this project focuses on the mechanism of formation of carbon-based low-friction tribofilms from organic lubricant additives. In particular, the importance of the chemical properties of the additives will be investigated with atomistic simulations following a bottom-up approach. The objectives of the project are the following: (i) Understand how the chemical properties of the additives influence their surface adsorption and tribochemistry. (ii) Understand what is the effect of mechanical stresses and temperature on the reaction paths for molecular decomposition. (iii) Use density functional theory calculations to train a machine-learned interatomic potential to accelerate the tribochemical simulations. (iv) Use the machine-learned potential to study cooperative effects between additives on the surfaces. (v) Use non-reactive molecular dynamics to connect the structure and the chemical properties of the tribofilms to their friction performance. (vi) Explore synergies and antagonisms of the lubricant molecules on different substrates. (vii) Develop an interface to a platform to organize and store the results of the simulations and their metadata, ensuring interoperability of the data between work packages and accessibility by the community. The results of this project will be essential to clarify the mechanism of formation of low-friction tribofilms and explain many overlooked aspects in the tribochemistry of these materials. The ultimate goal of the project is to offer a strategy for the design of sustainable and efficient lubricant additives.

• DFG Programme: Research Grants