The Effect of Anion Architecture on the Lubrication Chemistry of Phosphonium Orthoborate Ionic Liquid

Abstract 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. ToF-SIMS 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.

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The effect of anion architecture on the lubrication chemistry of phosphonium orthoborate ionic liquids

Scientific Reports ◽

10.1038/s41598-021-02763-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bulat Munavirov ◽

Jeffrey J. Black ◽

Faiz Ullah Shah ◽

Johan Leckner ◽

Mark W. Rutland ◽

...

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Self Assembly ◽

Secondary Ion Mass Spectrometry ◽

Film Formation ◽

Liquid Composition ◽

Mass Spectrometry Analysis ◽

Lubricant Layer ◽

Material Transport ◽

Spectrometry Analysis

AbstractPhosphonium 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.

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High throughput approach to investigating ternary solvents of aqueous non-stoichiometric protic ionic liquids

Physical Chemistry Chemical Physics ◽

10.1039/c8cp05894f ◽

2019 ◽

Vol 21 (13) ◽

pp. 6810-6827 ◽

Cited By ~ 5

Author(s):

Dilek Yalcin ◽

Calum J. Drummond ◽

Tamar L. Greaves

Keyword(s):

Surface Tension ◽

Ionic Liquid ◽

Ionic Liquids ◽

High Throughput ◽

Self Assembly ◽

Protic Ionic Liquids ◽

Systematic Data ◽

Solvent Systems ◽

Compositional Space

High throughput methods were used to investigate ionic liquid containing solutions to provide systematic data of a broad compositional space. We have principally focused on the surface tension, apparent pH and liquid nanostructure to identify potential self-assembly and protein stabilizing ability of solvent systems.

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Lyotropic liquid crystal phase behavior of a cationic amphiphile in aqueous and non-stoichiometric protic ionic liquid mixtures

Soft Matter ◽

10.1039/d0sm01298j ◽

2020 ◽

Vol 16 (41) ◽

pp. 9456-9470

Author(s):

Dilek Yalcin ◽

Calum J. Drummond ◽

Tamar L. Greaves

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Liquid Crystal ◽

Self Assembly ◽

Liquid Mixtures ◽

Lyotropic Liquid Crystal ◽

Liquid Crystal Phase ◽

Protic Ionic Liquids ◽

Protic Ionic Liquid ◽

Cationic Amphiphile

Protic ionic liquids (PILs) are the largest and most tailorable known class of non-aqueous solvents which possess the ability to support amphiphile self-assembly.

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Self-assembled lipase nanosphere templated one-pot biogenic synthesis of silica hollow spheres in ionic liquid [Bmim][PF6]

RSC Advances ◽

10.1039/c5ra22543d ◽

2015 ◽

Vol 5 (128) ◽

pp. 105800-105809 ◽

Cited By ~ 1

Author(s):

Sampa Sarkar ◽

Kshudiram Mantri ◽

Dinesh Kumar ◽

Suresh K. Bhargava ◽

Sarvesh K. Soni

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Structure Function ◽

Self Assembly ◽

Hollow Spheres ◽

Biogenic Synthesis ◽

One Pot ◽

Lipase Enzyme ◽

Self Assembled

Self-assembly of hydrophobic lipase enzyme in hydrophobic and hydrophilic ionic liquids and a correlation in structure–function and activity.

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Viscosities and Conductivities of [BMIM]Zn(Ac)xCly(x=0,1,2,3; y=3,2,1,0) Ionic Liquids at Different Temperatures

Journal of Chemistry ◽

10.1155/2017/7428097 ◽

2017 ◽

Vol 2017 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Hang Xu ◽

Dandan Zhang

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Arrhenius Equation ◽

Correlation Coefficients ◽

Conductivity Data ◽

Different Temperatures ◽

The Relationship

Viscosity and conductivity data of BMIMZnAcxCly(x=0,1,2,3; y=3,2,1,0) ionic liquids were detected at temperature ranging from 323.15 to 353.15 K with an interval of 5 K. The conductivities of different ionic liquids at the same temperature followed the trend [BMIM][ZnAcCl2] > [BMIM][ZnAc2Cl] > [BMIM][ZnCl3] > [BMIM][ZnAc3]. The viscosities of different ionic liquid abided by the order [BMIM][ZnCl3] > [BMIM][ZnAcCl2] > [BMIM][ZnAc2Cl] > [BMIM][ZnAc3]. Acetate ion could reduce the viscosity of ionic liquids. The relationship between viscosity/conductivity and temperature obeyed the Arrhenius equation and Vogel-Fulcher-Tammann (VFT) equation very well with above 0.99 correlation coefficients.

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pH triggered self-assembly structural transition of ionic liquids in aqueous solutions: smart use of pH-responsive additives

RSC Advances ◽

10.1039/c5ra12010a ◽

2015 ◽

Vol 5 (80) ◽

pp. 65583-65590 ◽

Cited By ~ 6

Author(s):

Huiyong Wang ◽

Bo Tan ◽

Hucheng Zhang ◽

Jianji Wang

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Aqueous Solutions ◽

Self Assembly ◽

Structural Transition ◽

Ph Value ◽

Ph Responsive ◽

Single Chain ◽

Solution Ph ◽

Spherical Micelles

The pH responsive fluids consisting of single-chain ionic liquid surfactants [Cnmim]Br (n = 12, 14) and hydrotropes can reversibly transform from spherical micelles to vesicles then to spherical micelles again with the change of the solution pH value.

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Friction and Wear Properties of Halogen-Free and Halogen-Containing Ionic Liquids Used As Neat Lubricants, Lubricant Additives and Thin Lubricant Layers

Volume 10: 2017 ASME International Power Transmission and Gearing Conference ◽

10.1115/detc2017-67971 ◽

2017 ◽

Author(s):

Hong Guo ◽

Rui Liu ◽

Alfonso Fuentes-Aznar ◽

Patricia Iglesias Victoria

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Friction And Wear ◽

Mineral Oil ◽

Surface Interactions ◽

Lubricant Additives ◽

Wear Properties ◽

Sem Images ◽

Wear Reduction ◽

Halogen Free

The lubricating ability of one halogen-free and one halogen-containing phosphonium-based ionic liquids are investigated as neat lubricants, lubricant additives and thin lubricant layers in steel-steel contact. The use of the ionic liquids in any of the three lubricating methods reduced friction and wear compared to a base mineral oil. The halogen-free ionic liquid outperformed the halogen-containing ionic liquid in the three methods of lubrication. The highest friction and wear reduction were obtained when ionic liquids were used as neat lubricants. Under this condition, friction reductions of 37.21% and 25.73 %, and wear reduction of 47.12% and 41.18% compared to the based mineral oil were obtained for the halogen-free and halogen-containing ionic liquids respectively. The wear mechanisms and surface interactions are discussed in terms of ionic liquid-metal surface interactions from optical and SEM images and EDS analysis.

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Tribochemistry and thermo-oxidative stability of halogen-free ionic liquids

RSC Advances ◽

10.1039/c7ra09163j ◽

2017 ◽

Vol 7 (77) ◽

pp. 48766-48776 ◽

Cited By ~ 6

Author(s):

Vladimir Totolin ◽

Lucia Pisarova ◽

Nicole Dörr ◽

Ichiro Minami

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Oxidative Stability ◽

Room Temperature ◽

Room Temperature Ionic Liquid ◽

Iron Phosphates ◽

Halogen Free ◽

First Time

The formation of binary iron phosphates/phosphides based tribofilms from a phosphonium phosphate room-temperature ionic liquid has been reported for the first time.

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Hydrophilic Ionic Liquids in the Synthesis of Hantzsch Ester

Latvian Journal of Chemistry ◽

10.2478/v10161-011-0064-6 ◽

2011 ◽

Vol 50 (3-4) ◽

pp. 277-283 ◽

Cited By ~ 1

Author(s):

S. Pavlovica ◽

E. Gzibovska ◽

A. Zicmanis ◽

P. Mekss ◽

M. Klavins

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Organic Solvents ◽

Heterocyclic Compound ◽

Reaction Rates ◽

Ester Synthesis ◽

Low Toxicity ◽

The Relationship

Hydrophilic Ionic Liquids in the Synthesis of Hantzsch Ester Hantzsch ester synthesis was investigated using (2-hydroxyethyl)-ammonium carboxylates, polar and hydrophilic ionic liquids possessing low toxicity and high biodegradability. The reaction rates and yields of the products in ionic liquids were greater than those in common organic solvents. The relationship between the structure of the ionic liquid used and the structure of the heterocyclic compound was investigated.

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