2025 AIChE Annual Meeting
(17b) A Multi-Scale Investigation of Organic Friction Modifiers at Solid/Liquid Interface
Authors
Zhenyu Zhang - Presenter, University of Birmingham
David Burgess, University of Birmingham
Peter Fryer, University of Birmingham
Ian McRobbie, Innospec Inc.
Jacqueline Reid, Innospec
To link molecular characteristics and lubrication performance of organic friction modifiers (OFMs), a multi-scale study was carried out to investigate the effects of functional groups and solvents on the tribological properties of two model OFMs, namely palmitic acid and pentadecylamine, at the oil-stainless steel interface. It was observed that the solvent composition has a profound effect on the surface adsorption and the interfacial adhesion force of the OFMs, showing vastly different values of adsorption kinetics and surface coverage. The presence of water within the organic solvents was found to have a considerable impact on the tribological performance. We were able to quantitatively correlate the nanotribological properties such as binding force and adsorption kinetics with the macroscopic testing results satisfactorily, which suggests that the static Coefficient of Friction (COF) is affected by the properties of the film formed in thermodynamic equilibrium, whilst the dynamic COF is related to the interfacial forces at the surface during sliding, and finally the wear on the solid surface is related to ability for the additives to rapidly re-adsorb once removed.