[SY-O6] Symposium O-6

[SY-O6] Atomistic simulations of amines as organic friction modifiers

Rafael Pereira de Matos¹, Sophie Loehlé², Clotilde Minfray¹, ^○Manuel Cobian¹ (1.LTDS ECL, Universite de Lyon, France, 2.TOTAL Marketing & Services, Solaize, France)

Amines molecules can be used as organic friction modifiers OFM in a
lubricated contact working under in mixed/boundary regime.
Several experimental studies have been already done using steel against
steel contact. Our aim is to propose
a computational simulation protocol to have a better understanding of
what happens at atomic scale in the contact.
We study some physical properties (density, diffusivity) of amines
blended in Poly Alpha Olephin PAO using
molecular dynamics MD simulations employing the OPLS force field.
Green-Kubo formalism gives us access to diffusion coeficients of amines
in the oil.
Then, we present ab-initio (DFT+U based) study of the adsorption of
this OFM on alpha-hematite Fe2O3 surface {01-12}.
The interactions between the amine molecule and the surface will be
analysed and used to fit Lennard-Jones potential
to model the interaction and open the way to new simulations using
molecular dynamics.
We will conclude presenting simulations of the friction process
applying stress and shear and computing a
numerical coefficient of friction.