Layered Structure and Wear Mechanism of Concentrated Polymer Brushes

Concentrated polymer brushes (CPBs), which are significantly denser and thicker than conventional semidilute polymer brushes, have received increasing attention in the field of tribology because of their superlow friction properties. However, despite numerous studies aimed at enhancing CPBs for mech...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 39(2023), 50 vom: 19. Dez., Seite 18458-18465
1. Verfasser: Okubo, Hikaru (VerfasserIn)
Weitere Verfasser: Kagiwata, Daiki, Nakano, Ken, Tsujii, Yoshinobu
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2023
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:Concentrated polymer brushes (CPBs), which are significantly denser and thicker than conventional semidilute polymer brushes, have received increasing attention in the field of tribology because of their superlow friction properties. However, despite numerous studies aimed at enhancing CPBs for mechanical applications, the relationship between the specific layered structure and lubrication mechanisms of CPBs is still not completely understood. In this study, to reveal the relationship, simultaneous time-resolved measurements of the interfacial gap, static mechanical response, and dynamic mechanical response of the CPB at the contact interface were conducted using optical interference and precise force measuring methods. Two types of tests (i.e., the "indentation" and "sliding" tests) were alternately performed on a glass substrate coated with the CPB against a steel ball immersed in an ionic liquid. The indentation tests measuring the time-resolved interfacial gap and changes in static and dynamic mechanical responses quantitatively confirmed the presence of dilute, middle, and concentrated layers in the CPB. In the sliding tests, the wear of the CPB was detected by observing a decrease in the interfacial gap at the contact interface. Moreover, the thickness of the dilute layer remained constant with sliding, whereas the thicknesses of the other layers decreased, indicating that the dilute layer was continuously formed due to sliding. Therefore, CPB wear occurs randomly at the friction interface alongside the formation of a dilute layer with low density and stiffness on the surface
Beschreibung:Date Revised 23.12.2023
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.3c02751