List of Journal Publications
2022
2.
Bian, Jianjun, Nicola, L.
Lubrication of rough copper with few-layer graphene Journal Article
In: TRIBOLOGY INTERNATIONAL, vol. 173, 2022.
Abstract | BibTeX | Tags: friction, Graphene, Interlocking, Rough surface | Links:
@article{Bian2022a,
title = {Lubrication of rough copper with few-layer graphene},
author = {Jianjun Bian and L. Nicola},
doi = {10.1016/j.triboint.2022.107621},
year = {2022},
date = {2022-01-01},
journal = {TRIBOLOGY INTERNATIONAL},
volume = {173},
publisher = {ELSEVIER SCI LTD},
abstract = {It has been demonstrated through experiments and simulations that friction decreases significantly when graphene is used as a solid lubricant on various materials. However, the effect of increasing the number of graphene layers on lubrication is controversial. Some studies predict an increase of friction with the number of layers that can be imputed to increased contact area, others a decrease in friction attributed to increased flexural rigidity of the layers. Herein, atomistic simulations are performed to investigate the atomic mechanisms by which few-layers graphene lubricate rough copper surfaces when probed by a smooth tip. The results of the simulations show that increasing the number of graphene layers drastically reduces friction, while the deformation mechanism is found to change from atomic wear to recoverable flattening of surface steps, as the amount of interlocking between the surfaces is reduced.},
keywords = {friction, Graphene, Interlocking, Rough surface},
pubstate = {published},
tppubtype = {article}
}
It has been demonstrated through experiments and simulations that friction decreases significantly when graphene is used as a solid lubricant on various materials. However, the effect of increasing the number of graphene layers on lubrication is controversial. Some studies predict an increase of friction with the number of layers that can be imputed to increased contact area, others a decrease in friction attributed to increased flexural rigidity of the layers. Herein, atomistic simulations are performed to investigate the atomic mechanisms by which few-layers graphene lubricate rough copper surfaces when probed by a smooth tip. The results of the simulations show that increasing the number of graphene layers drastically reduces friction, while the deformation mechanism is found to change from atomic wear to recoverable flattening of surface steps, as the amount of interlocking between the surfaces is reduced.
2021
1.
Bian, J., Nicola, L.
On the lubrication of rough copper surfaces with graphene Journal Article
In: TRIBOLOGY INTERNATIONAL, vol. 156, 2021.
Abstract | BibTeX | Tags: friction, Graphene, Lubrication, Rough surface | Links:
@article{Bian2021,
title = {On the lubrication of rough copper surfaces with graphene},
author = {J. Bian and L. Nicola},
doi = {10.1016/j.triboint.2020.106837},
year = {2021},
date = {2021-01-01},
journal = {TRIBOLOGY INTERNATIONAL},
volume = {156},
publisher = {Elsevier Ltd},
abstract = {Graphene is well known as a solid lubricant for nanoscale devices and is generally used to decrease friction between flat surfaces. In this work, we investigate its performance as a lubricant for rough surfaces. To this end, the problem of a silicon tip sliding on a rough copper single crystal, bare or covered by a graphene layer, is addressed through molecular dynamics simulations. To simplify the analysis, the copper crystal is taken to be quasi-three dimensional, so that the roughness profile is constant along the short periodic dimension. Results show markedly different deformation mechanisms in copper, depending on whether the rough surface is bare, covered with a stretched graphene layer, or with a wrinkled graphene layer. The wrinkled layer appears to be the best solution to reduce friction.},
keywords = {friction, Graphene, Lubrication, Rough surface},
pubstate = {published},
tppubtype = {article}
}
Graphene is well known as a solid lubricant for nanoscale devices and is generally used to decrease friction between flat surfaces. In this work, we investigate its performance as a lubricant for rough surfaces. To this end, the problem of a silicon tip sliding on a rough copper single crystal, bare or covered by a graphene layer, is addressed through molecular dynamics simulations. To simplify the analysis, the copper crystal is taken to be quasi-three dimensional, so that the roughness profile is constant along the short periodic dimension. Results show markedly different deformation mechanisms in copper, depending on whether the rough surface is bare, covered with a stretched graphene layer, or with a wrinkled graphene layer. The wrinkled layer appears to be the best solution to reduce friction.
