Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity System
The application range of superlubricity systems can be extended effectively by realizing an adjustable friction coefficient. In this study, a stable poly(vinylphosphonic acid) (PVPA) superlubricity system was developed using sodium chloride (NaCl) solution as the lubricant. A sudden increase in the...
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| Format: | Article |
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MDPI AG
2022-08-01
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| Series: | Lubricants |
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| Online Access: | https://www.mdpi.com/2075-4442/10/8/191 |
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| author | Mengmeng Liu Caixia Zhang Lihui Wang Yanhong Cheng Ying Li Lianpeng Bai Zhifeng Liu |
| author_facet | Mengmeng Liu Caixia Zhang Lihui Wang Yanhong Cheng Ying Li Lianpeng Bai Zhifeng Liu |
| author_sort | Mengmeng Liu |
| collection | DOAJ |
| description | The application range of superlubricity systems can be extended effectively by realizing an adjustable friction coefficient. In this study, a stable poly(vinylphosphonic acid) (PVPA) superlubricity system was developed using sodium chloride (NaCl) solution as the lubricant. A sudden increase in the friction coefficient occurred when a trivalent salt solution was introduced to the base lubricant during the friction process. The changes in surface microstructure and interfacial molecular behavior induced by trivalent cations were studied by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and molecular dynamics simulation. The regulation mechanism of trivalent cations with respect to the friction coefficient of the PVPA superlubricity system was explored. Although La<sup>3+</sup> and Fe<sup>3+</sup> in solutions exist in two forms (La<sup>3+</sup> and Fe(OH)<sub>3</sub>), both can destroy the stable coating structure through a bridging effect, resulting in a sudden increase in the friction coefficient. The ability of various cations to attract the surrounding water molecules is an important reason for the varying degree of change of the friction coefficient. In addition, the degree of sudden increase in the friction coefficient is dependent on the concentration of trivalent cations. There is an extreme concentration at which the maximum sudden increase degree in friction coefficient can be obtained. This study provides insights into the realization of oil-based superlubricity through interface regulation. |
| first_indexed | 2024-03-09T13:04:41Z |
| format | Article |
| id | doaj.art-5c379e9541194f41a74b04aa7bb2658d |
| institution | Directory Open Access Journal |
| issn | 2075-4442 |
| language | English |
| last_indexed | 2024-03-09T13:04:41Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Lubricants |
| spelling | doaj.art-5c379e9541194f41a74b04aa7bb2658d2023-11-30T21:50:13ZengMDPI AGLubricants2075-44422022-08-0110819110.3390/lubricants10080191Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity SystemMengmeng Liu0Caixia Zhang1Lihui Wang2Yanhong Cheng3Ying Li4Lianpeng Bai5Zhifeng Liu6Institute of Advanced Manufacturing and Intelligent Technology, Department of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, ChinaInstitute of Advanced Manufacturing and Intelligent Technology, Department of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, ChinaInstitute of Advanced Manufacturing and Intelligent Technology, Department of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, ChinaInstitute of Advanced Manufacturing and Intelligent Technology, Department of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, ChinaInstitute of Advanced Manufacturing and Intelligent Technology, Department of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, ChinaInstitute of Advanced Manufacturing and Intelligent Technology, Department of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, ChinaInstitute of Advanced Manufacturing and Intelligent Technology, Department of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, ChinaThe application range of superlubricity systems can be extended effectively by realizing an adjustable friction coefficient. In this study, a stable poly(vinylphosphonic acid) (PVPA) superlubricity system was developed using sodium chloride (NaCl) solution as the lubricant. A sudden increase in the friction coefficient occurred when a trivalent salt solution was introduced to the base lubricant during the friction process. The changes in surface microstructure and interfacial molecular behavior induced by trivalent cations were studied by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and molecular dynamics simulation. The regulation mechanism of trivalent cations with respect to the friction coefficient of the PVPA superlubricity system was explored. Although La<sup>3+</sup> and Fe<sup>3+</sup> in solutions exist in two forms (La<sup>3+</sup> and Fe(OH)<sub>3</sub>), both can destroy the stable coating structure through a bridging effect, resulting in a sudden increase in the friction coefficient. The ability of various cations to attract the surrounding water molecules is an important reason for the varying degree of change of the friction coefficient. In addition, the degree of sudden increase in the friction coefficient is dependent on the concentration of trivalent cations. There is an extreme concentration at which the maximum sudden increase degree in friction coefficient can be obtained. This study provides insights into the realization of oil-based superlubricity through interface regulation.https://www.mdpi.com/2075-4442/10/8/191poly(vinylphosphonic acid) (PVPA) coatingLa<sup>3+</sup>Fe(OH)<sub>3</sub>bridging effectconcentration-dependent |
| spellingShingle | Mengmeng Liu Caixia Zhang Lihui Wang Yanhong Cheng Ying Li Lianpeng Bai Zhifeng Liu Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity System Lubricants poly(vinylphosphonic acid) (PVPA) coating La<sup>3+</sup> Fe(OH)<sub>3</sub> bridging effect concentration-dependent |
| title | Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity System |
| title_full | Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity System |
| title_fullStr | Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity System |
| title_full_unstemmed | Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity System |
| title_short | Regulation Mechanism of Trivalent Cations on Friction Coefficient of a Poly(Vinylphosphonic Acid) (PVPA) Superlubricity System |
| title_sort | regulation mechanism of trivalent cations on friction coefficient of a poly vinylphosphonic acid pvpa superlubricity system |
| topic | poly(vinylphosphonic acid) (PVPA) coating La<sup>3+</sup> Fe(OH)<sub>3</sub> bridging effect concentration-dependent |
| url | https://www.mdpi.com/2075-4442/10/8/191 |
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