The effect of anion architecture on the lubrication chemistry of phosphonium orthoborate ionic liquidsShow others and affiliations
2021 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, no 1, article id 24021
Article in journal (Refereed) Published
Abstract [en]
Phosphonium ionic liquids with orthoborate anions have been studied in terms of their interfacial film formation, both physisorbed and sacrificial from chemical breakdown, in sheared contacts of varying harshness. The halogen-free anion architecture was varied through (i) the heteronuclear ring size, (ii) the hybridisation of the constituent atoms, and (iii) the addition of aryl functionalities. Time of Flight-Secondary Ion Mass Spectrometry analysis revealed the extent of sacrificial tribofilm formation allowing the relative stability of the ionic liquids under tribological conditions to be determined and their breakdown mechanisms to be compared to simple thermal decomposition. Overall, ionic liquids outperformed reference oils as lubricants; in some cases, sacrificial films were formed (with anion breakdown a necessary precursor to phosphonium cation decomposition) while in other cases, a protective, self-assembly lubricant layer or hybrid film was formed. The salicylate-based anion was the most chemically stable and decomposed only slightly even under the harshest conditions. It was further found that surface topography influenced the degree of breakdown through enhanced material transport and replenishment. This work thus unveils the relationship between ionic liquid composition and structure, and the ensuing inter- and intra-molecular interactions and chemical stability, and demonstrates the intrinsic tuneability of an ionic liquid lubrication technology. © 2021, The Author(s).
Place, publisher, year, edition, pages
Nature Research , 2021. Vol. 11, no 1, article id 24021
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:ri:diva-57503DOI: 10.1038/s41598-021-02763-5Scopus ID: 2-s2.0-85121368601OAI: oai:DiVA.org:ri-57503DiVA, id: diva2:1623736
Note
Funding details: Centre of Excellence for Environmental Decisions, Australian Research Council, CEED; Funding details: Centre of Excellence for Core to Crust Fluid Systems, Australian Research Council, CCFS, ARC; Funding details: Centre of Excellence for Integrative Brain Function, Australian Research Council, CIBF; Funding details: Centre of Excellence for Coral Reef Studies, Australian Research Council; Funding details: Australian Research Council, ARC, DP180103682; Funding details: Stiftelsen för Strategisk Forskning, SSF, EM16-0013; Funding details: Centre of Excellence for Particle Physics at the Terascale, Australian Research Council, CoEPP; Funding details: Centre of Excellence in Cognition and its Disorders, Australian Research Council, CCD; Funding details: Knut och Alice Wallenbergs Stiftelse, KAW2012.0078; Funding details: Kungliga Tekniska Högskolan, KTH; Funding details: Vetenskapsrådet, VR, 2018-05017; Funding details: Centre of Excellence in Plant Energy Biology, Australian Research Council, PEB; Funding details: Centre of Excellence for Coherent X-Ray Science, Australian Research Council, CXS; Funding details: Centre of Excellence for Electromaterials Science, Australian Research Council, ARC, ACES; Funding details: Training Centre for Food and Beverage Supply Chain Optimisation, Australian Research Council; Funding details: Centre of Excellence in Future Low-Energy Electronics Technologies, Australian Research Council, FLEET; Funding text 1: The Swedish Foundation for Strategic Research (project EM16-0013), the Knut and Alice Wallenberg Foundation (project KAW2012.0078), the Swedish Research Council (project 2018-05017) and the Australian Research Council Discovery Programme (project supported in part by DP180103682) are gratefully acknowledged for financial support.
2021-12-302021-12-302023-10-31Bibliographically approved