Tribochemical reactions are chemical processes, usually involving lubricant or environment molecules, activated at the interface between two solids in relative motion. They are difficult to be monitored in situ, which leaves a gap in the atomistic understanding required for their control. Here we report the real-time atomistic description of the tribochemical reactions occurring at the interface between two diamond films in relative motion, by means of large scale ab initio molecular dynamics. We show that the load-induced confinement is able to catalyze diamond passivation by water dissociative adsorption. Such passivation decreases the energy of the contacting surfaces and increases their electronic repulsion. At sufficiently high coverages, the latter prevents surface sealing, thus lowering friction. Our findings elucidate effects of the nanoscale confinement on reaction kinetics and surface thermodynamics, which are important for the design of new lubricants. © 2013 American Physical Society.

Load-induced confinement activates diamond lubrication by water / Zilibotti, Giovanna; Corni, S.; Righi, Maria Clelia. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 111:(2013), pp. 146101-146105. [10.1103/PhysRevLett.111.146101]

Load-induced confinement activates diamond lubrication by water

ZILIBOTTI, Giovanna;RIGHI, Maria Clelia
2013

Abstract

Tribochemical reactions are chemical processes, usually involving lubricant or environment molecules, activated at the interface between two solids in relative motion. They are difficult to be monitored in situ, which leaves a gap in the atomistic understanding required for their control. Here we report the real-time atomistic description of the tribochemical reactions occurring at the interface between two diamond films in relative motion, by means of large scale ab initio molecular dynamics. We show that the load-induced confinement is able to catalyze diamond passivation by water dissociative adsorption. Such passivation decreases the energy of the contacting surfaces and increases their electronic repulsion. At sufficiently high coverages, the latter prevents surface sealing, thus lowering friction. Our findings elucidate effects of the nanoscale confinement on reaction kinetics and surface thermodynamics, which are important for the design of new lubricants. © 2013 American Physical Society.
2013
111
146101
146105
Load-induced confinement activates diamond lubrication by water / Zilibotti, Giovanna; Corni, S.; Righi, Maria Clelia. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 111:(2013), pp. 146101-146105. [10.1103/PhysRevLett.111.146101]
Zilibotti, Giovanna; Corni, S.; Righi, Maria Clelia
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1100937
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