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Copper nanoparticles - a promising additive for lubrication of hydrogen technology

Copper nanoparticles - a promising additive for lubrication of hydrogen technology
Copper nanoparticles - a promising additive for lubrication of hydrogen technology
Bearings used in hydrogen technology face significant lubrication challenges. The main difficulty stems from hydrogen molecules dissociating into atoms on the nascent wear sites and diffusing into steel, ultimately causing hydrogen embrittlement and failure of tribological components. Lubricant additives that rapidly form tribofilms such as antiwear and extreme pressure additives can suppress atomic hydrogen generation and permeation in steel, but the resulting tribofilms tend to increase friction. Nanol™, a sustainable copper-based nano additive capable of forming stable dispersions in oils, offers unique friction modifying, antiwear and thermal advantages. In this study, Nanol™ dispersed in a polyalphaolefin base oil was used to lubricate ball and roller bearings undergoing rolling contact fatigue tests under boundary lubrication conditions in a hydrogen environment. Beyond its ability to reduce friction by immediately decreasing the real contact area between the moving parts, Nanol™ also reacts with nascent iron to form cohesive, low friction tribofilms composed of copper and iron oleate on the wear track. These mechanisms, along with the properties of the chemically formed tribofilm were key to lowering friction and extend the fatigue life of the bearings operating in hydrogen and under severe conditions.
boundary lubrication, films, friction, lubricant additives, nano-tribology, rolling element bearings, rolling fatigue, wear
0742-4787
062102-1-062102-13
Ratoi, Monica
cfeffe10-31ca-4630-8399-232c4bc2beff
Tanaka, Hiroyoshi
3590bace-54f9-4647-b10f-2852c25f9f36
Cernalevschi, Grigore
ca2caf51-7476-420a-a266-2aaeda2e85de
Sugimura, Joichi
0bd99696-0d1c-413a-8e8b-9a4a7001fb70
Ratoi, Monica
cfeffe10-31ca-4630-8399-232c4bc2beff
Tanaka, Hiroyoshi
3590bace-54f9-4647-b10f-2852c25f9f36
Cernalevschi, Grigore
ca2caf51-7476-420a-a266-2aaeda2e85de
Sugimura, Joichi
0bd99696-0d1c-413a-8e8b-9a4a7001fb70

Ratoi, Monica, Tanaka, Hiroyoshi, Cernalevschi, Grigore and Sugimura, Joichi (2026) Copper nanoparticles - a promising additive for lubrication of hydrogen technology. Journal of Tribology: Transactions of the ASME, 148 (6), 062102-1-062102-13, [TRIB-25-1609]. (doi:10.1115/1.4070808).

Record type: Article

Abstract

Bearings used in hydrogen technology face significant lubrication challenges. The main difficulty stems from hydrogen molecules dissociating into atoms on the nascent wear sites and diffusing into steel, ultimately causing hydrogen embrittlement and failure of tribological components. Lubricant additives that rapidly form tribofilms such as antiwear and extreme pressure additives can suppress atomic hydrogen generation and permeation in steel, but the resulting tribofilms tend to increase friction. Nanol™, a sustainable copper-based nano additive capable of forming stable dispersions in oils, offers unique friction modifying, antiwear and thermal advantages. In this study, Nanol™ dispersed in a polyalphaolefin base oil was used to lubricate ball and roller bearings undergoing rolling contact fatigue tests under boundary lubrication conditions in a hydrogen environment. Beyond its ability to reduce friction by immediately decreasing the real contact area between the moving parts, Nanol™ also reacts with nascent iron to form cohesive, low friction tribofilms composed of copper and iron oleate on the wear track. These mechanisms, along with the properties of the chemically formed tribofilm were key to lowering friction and extend the fatigue life of the bearings operating in hydrogen and under severe conditions.

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Accepted/In Press date: 19 December 2025
Published date: 16 February 2026
Keywords: boundary lubrication, films, friction, lubricant additives, nano-tribology, rolling element bearings, rolling fatigue, wear

Identifiers

Local EPrints ID: 509329
URI: http://eprints.soton.ac.uk/id/eprint/509329
ISSN: 0742-4787
PURE UUID: ca6739b2-8de1-4831-b3aa-466687b049d3
ORCID for Monica Ratoi: ORCID iD orcid.org/0000-0001-8400-3054

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Date deposited: 18 Feb 2026 17:48
Last modified: 19 Feb 2026 02:42

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Contributors

Author: Monica Ratoi ORCID iD
Author: Hiroyoshi Tanaka
Author: Grigore Cernalevschi
Author: Joichi Sugimura

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