An All-Atom Force Field for Dry and Water-Lubricated Carbon Tribological Interfaces

Fuente: arXiv
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Main Authors: Reichenbach, Thomas, Sylla, Severin, Mayrhofer, Leonhard, Romero, Pedro Antonio, Schwarz, Paul, Moseler, Michael, Moras, Gianpietro
Format: Preprint
Published: 2023
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author Reichenbach, Thomas
Sylla, Severin
Mayrhofer, Leonhard
Romero, Pedro Antonio
Schwarz, Paul
Moseler, Michael
Moras, Gianpietro
author_facet Reichenbach, Thomas
Sylla, Severin
Mayrhofer, Leonhard
Romero, Pedro Antonio
Schwarz, Paul
Moseler, Michael
Moras, Gianpietro
contents We present a non-reactive force field for molecular dynamics simulations of interfaces between passivated amorphous surfaces and their interaction with water. The force field enables large-scale dynamic simulations of dry and lubricated tribological contacts and is tailored to surfaces with hydrogen, hydroxyl and aromatic surface passivation. To favour its compatibility with existing force-field parameterizations for liquids and allow a straightforward extension to other types of surface passivation species, we adopt the commonly used OPLS functional form. The optimisation of the force-field parameters is systematic and follows a protocol that can be reused for other surface-molecule combinations. Reference data are calculated with gradient- and dispersion-corrected density functional theory and include the bonding structure and elastic deformation of bulk and surface structures as well as surface adhesion and water adsorption energy landscapes. The conventions adopted to define the different force-field atom types are based on the hybridisation of carbon orbitals and enable a simple and efficient parameter optimisation strategy based on quantum-mechanical calculations performed only on crystalline reference structures. Transferability tests on amorphous interfaces demonstrate the effectiveness of this approach. After testing the force field, we present two examples of application to tribological problems. Namely, we investigate relationships between dry friction and the corrugation of the contact potential energy surface and the dependency of friction on the thickness of interface water films. We finally discuss the limitations of the force field and propose strategies for its improvement and extension.
format Preprint
id arxiv_https___arxiv_org_abs_2310_12619
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle An All-Atom Force Field for Dry and Water-Lubricated Carbon Tribological Interfaces
Reichenbach, Thomas
Sylla, Severin
Mayrhofer, Leonhard
Romero, Pedro Antonio
Schwarz, Paul
Moseler, Michael
Moras, Gianpietro
Materials Science
We present a non-reactive force field for molecular dynamics simulations of interfaces between passivated amorphous surfaces and their interaction with water. The force field enables large-scale dynamic simulations of dry and lubricated tribological contacts and is tailored to surfaces with hydrogen, hydroxyl and aromatic surface passivation. To favour its compatibility with existing force-field parameterizations for liquids and allow a straightforward extension to other types of surface passivation species, we adopt the commonly used OPLS functional form. The optimisation of the force-field parameters is systematic and follows a protocol that can be reused for other surface-molecule combinations. Reference data are calculated with gradient- and dispersion-corrected density functional theory and include the bonding structure and elastic deformation of bulk and surface structures as well as surface adhesion and water adsorption energy landscapes. The conventions adopted to define the different force-field atom types are based on the hybridisation of carbon orbitals and enable a simple and efficient parameter optimisation strategy based on quantum-mechanical calculations performed only on crystalline reference structures. Transferability tests on amorphous interfaces demonstrate the effectiveness of this approach. After testing the force field, we present two examples of application to tribological problems. Namely, we investigate relationships between dry friction and the corrugation of the contact potential energy surface and the dependency of friction on the thickness of interface water films. We finally discuss the limitations of the force field and propose strategies for its improvement and extension.
title An All-Atom Force Field for Dry and Water-Lubricated Carbon Tribological Interfaces
topic Materials Science
url https://arxiv.org/abs/2310.12619