Experimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal Surfaces
Organophosphates are well-known as the canonical additives for lubricants. Thus, understanding of the additive behaviour is a key aspect in the design of films on metal surfaces. Different types of phosphates are added to improve their antiwear properties, but the contributions of individual esters...
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| Format: | Article |
| Language: | English |
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Japanese Society of Tribologists
2024-02-01
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| Series: | Tribology Online |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/trol/19/1/19_11/_pdf/-char/en |
| _version_ | 1797214477908705280 |
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| author | Hiroaki Koshima Ai Hamano Hiroshi Tokairin Yuko Murakami Hitoshi Washizu |
| author_facet | Hiroaki Koshima Ai Hamano Hiroshi Tokairin Yuko Murakami Hitoshi Washizu |
| author_sort | Hiroaki Koshima |
| collection | DOAJ |
| description | Organophosphates are well-known as the canonical additives for lubricants. Thus, understanding of the additive behaviour is a key aspect in the design of films on metal surfaces. Different types of phosphates are added to improve their antiwear properties, but the contributions of individual esters to these properties has not been studied using a combination of practical and theoretical approaches. In this study, organophosphates were isolated with high purity and their tribological characteristics were evaluated by using a Bowden-type reciprocating friction tester and a four-ball wear tester. Mono-oleylphosphate had a lower friction than di-oleylphosphate and exhibited excellent antiwear characteristics. Analysis of the sliding surfaces using desorption electrospray ionization-mass spectrometry (DESI-MS) and X-ray photoelectron spectroscopy (XPS) indicated that the film structure could predict the occurrence factor of the tribological characteristics of the oleylphosphates. Then the adsorption energies of the monoester on iron and iron oxide surfaces were higher than those of the diester, as assessed using density functional theory (DFT) calculations, owing to the difference in their chemisorption processes, as confirmed by further DFT analysis. Studies on the reactivity of additives and their interactions with surfaces are important for understanding the tribochemistry of additives. |
| first_indexed | 2024-04-24T11:14:48Z |
| format | Article |
| id | doaj.art-46f7fb81940d4262b94c3fd4fd8cf491 |
| institution | Directory Open Access Journal |
| issn | 1881-2198 |
| language | English |
| last_indexed | 2024-04-24T11:14:48Z |
| publishDate | 2024-02-01 |
| publisher | Japanese Society of Tribologists |
| record_format | Article |
| series | Tribology Online |
| spelling | doaj.art-46f7fb81940d4262b94c3fd4fd8cf4912024-04-11T09:43:09ZengJapanese Society of TribologistsTribology Online1881-21982024-02-01191112210.2474/trol.19.11trolExperimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal SurfacesHiroaki Koshima0Ai Hamano1Hiroshi Tokairin2Yuko Murakami3Hitoshi Washizu4Lubricants Research Laboratory, Idemitsu Kosan Co.,Ltd.Advanced Technology Research Laboratories, Idemitsu Kosan Co.,Ltd.Advanced Technology Research Laboratories, Idemitsu Kosan Co.,Ltd.Advanced Technology Research Laboratories, Idemitsu Kosan Co.,Ltd.Graduate School of Simulation Studies, University of HyogoOrganophosphates are well-known as the canonical additives for lubricants. Thus, understanding of the additive behaviour is a key aspect in the design of films on metal surfaces. Different types of phosphates are added to improve their antiwear properties, but the contributions of individual esters to these properties has not been studied using a combination of practical and theoretical approaches. In this study, organophosphates were isolated with high purity and their tribological characteristics were evaluated by using a Bowden-type reciprocating friction tester and a four-ball wear tester. Mono-oleylphosphate had a lower friction than di-oleylphosphate and exhibited excellent antiwear characteristics. Analysis of the sliding surfaces using desorption electrospray ionization-mass spectrometry (DESI-MS) and X-ray photoelectron spectroscopy (XPS) indicated that the film structure could predict the occurrence factor of the tribological characteristics of the oleylphosphates. Then the adsorption energies of the monoester on iron and iron oxide surfaces were higher than those of the diester, as assessed using density functional theory (DFT) calculations, owing to the difference in their chemisorption processes, as confirmed by further DFT analysis. Studies on the reactivity of additives and their interactions with surfaces are important for understanding the tribochemistry of additives.https://www.jstage.jst.go.jp/article/trol/19/1/19_11/_pdf/-char/entribologylubricantphosphatefrictionweardesi-msxpssimulation |
| spellingShingle | Hiroaki Koshima Ai Hamano Hiroshi Tokairin Yuko Murakami Hitoshi Washizu Experimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal Surfaces Tribology Online tribology lubricant phosphate friction wear desi-ms xps simulation |
| title | Experimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal Surfaces |
| title_full | Experimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal Surfaces |
| title_fullStr | Experimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal Surfaces |
| title_full_unstemmed | Experimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal Surfaces |
| title_short | Experimental and Theoretical Study on the Tribological Characteristics of Organophosphates on Metal Surfaces |
| title_sort | experimental and theoretical study on the tribological characteristics of organophosphates on metal surfaces |
| topic | tribology lubricant phosphate friction wear desi-ms xps simulation |
| url | https://www.jstage.jst.go.jp/article/trol/19/1/19_11/_pdf/-char/en |
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