On the Ionic Liquid Film ‘Pinned’ by Core-Shell Structured Fe3O4@Carbon Nanoparticles and Their Tribological PropertiesShow others and affiliations
2019 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 48, p. 26387-26398Article in journal (Refereed) Published
Abstract [en]
A strongly ‘pinned’ ionic liquid (IL, [BMIM][PF6]) film onto silicon (Si) surface via carbon capsuled Fe3O4 core-shell (Fe3O4@C) nanoparticles is achieved, revealing excellent friction-reducing ability at a high load. The adhesion force is measured as ~ 198 nN at the Fe3O4@C-Si interface by Fe3O4@C colloidal AFM tip, which is stronger than that at both Fe3O4@C-Fe3O4@C (~ 60 nN) and IL-Si (~ 10 nN) interfaces, indicating a strong ‘normal pin-force’ towards the Si substrate. The resulting strengthened force enables the formation of lateral IL networks via the dipole-dipole attractions among Fe3O4 cores. The observed blue shift of the characteristic band related to the IL anion in ATR-FTIR spectra confirmed the enhanced interaction. The N-Si, P-O chemical bonds formed as a result of the IL interactions with the Si substrate confirmed by XPS spectroscopy suggested that the IL lay on the Si plane. This orientation is favorable for Fe3O4@C nanoparticles to exert ‘normal pin-force’ and press the IL film strongly onto surfaces. The IL ios/clusters are thus anchored by these Fe3O4@C ‘pins’ onto the substrate to form a dense film, resulting in a smaller interaction size parameter, which is responsible for the reduced friction coefficient μ.
Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019. Vol. 21, no 48, p. 26387-26398
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
URN: urn:nbn:se:ltu:diva-76830DOI: 10.1039/C9CP05905AISI: 000502767400008PubMedID: 31793566Scopus ID: 2-s2.0-85076382284OAI: oai:DiVA.org:ltu-76830DiVA, id: diva2:1372451
Note
Validerad;2020;Nivå 2;2019-12-16 (johcin)
2019-11-232019-11-232020-08-26Bibliographically approved