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Li S, Hammond OS, Nelson A, de Campo L, Moir M, Recsei C, Shimpi MR, Glavatskih S, Pilkington GA, Mudring AV, Rutland MW. Anion Architecture Controls Structure and Electroresponsivity of Anhalogenous Ionic Liquids in a Sustainable Fluid. J Phys Chem B 2024; 128:4231-4242. [PMID: 38639329 DOI: 10.1021/acs.jpcb.3c08189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Three nonhalogenated ionic liquids (ILs) dissolved in 2-ethylhexyl laurate (2-EHL), a biodegradable oil, are investigated in terms of their bulk and electro-interfacial nanoscale structures using small-angle neutron scattering (SANS) and neutron reflectivity (NR). The ILs share the same trihexyl(tetradecyl)phosphonium ([P6,6,6,14]+) cation paired with different anions, bis(mandelato)borate ([BMB]-), bis(oxalato)borate ([BOB]-), and bis(salicylato)borate ([BScB]-). SANS shows a high aspect ratio tubular self-assembly structure characterized by an IL core of alternating cations and anions with a 2-EHL-rich shell or corona in the bulk, the geometry of which depends upon the anion structure and concentration. NR also reveals a solvent-rich interfacial corona layer. Their electro-responsive behavior, pertaining to the structuring and composition of the interfacial layers, is also influenced by the anion identity. [P6,6,6,14][BOB] exhibits distinct electroresponsiveness to applied potentials, suggesting an ion exchange behavior from cation-dominated to anion-rich. Conversely, [P6,6,6,14][BMB] and [P6,6,6,14][BScB] demonstrate minimal electroresponses across all studied potentials, related to their different dissociative and diffusive behavior. A mixed system is dominated by the least soluble IL but exhibits an increase in disorder. This work reveals the subtlety of anion architecture in tuning bulk and electro-interfacial properties, offering valuable molecular insights for deploying nonhalogenated ILs as additives in biodegradable lubricants and supercapacitors.
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Affiliation(s)
- Sichao Li
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm SE-100 44, Sweden
| | - Oliver S Hammond
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm SE-114 18, Sweden
- intelligent Advanced Materials, Department of Biological & Chemical Engineering and iNANO, Aarhus University, Aarhus C 8000, Denmark
| | - Andrew Nelson
- Australian Centre for Neutron Scattering, ANSTO, Lucas Heights, New South Wales 2234, Australia
| | - Liliana de Campo
- Australian Centre for Neutron Scattering, ANSTO, Lucas Heights, New South Wales 2234, Australia
| | - Michael Moir
- National Deuteration Facility, ANSTO, Lucas Heights, New South Wales 2234, Australia
| | - Carl Recsei
- National Deuteration Facility, ANSTO, Lucas Heights, New South Wales 2234, Australia
| | - Manishkumar R Shimpi
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm SE-114 18, Sweden
- Chemistry of Interfaces, Department of Civil and Environmental Engineering, Luleå University of Technology, Luleå SE-97187, Sweden
| | - Sergei Glavatskih
- System and Component Design, Department of Engineering Design, KTH Royal Institute of Technology, Stockholm SE-100 44, Sweden
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
- Department of Electromechanical, Systems and Metal Engineering, Ghent University, Ghent B-9052, Belgium
| | - Georgia A Pilkington
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm SE-100 44, Sweden
| | - Anja-Verena Mudring
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm SE-114 18, Sweden
- intelligent Advanced Materials, Department of Biological & Chemical Engineering and iNANO, Aarhus University, Aarhus C 8000, Denmark
- Department of Physics, Umeå University, Umeå SE-901 87, Sweden
| | - Mark W Rutland
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm SE-100 44, Sweden
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
- Bioeconomy and Health Department Materials and Surface Design, RISE Research Institutes of Sweden, Stockholm SE-114 28, Sweden
- Laboratoire de Tribologie et Dynamique des Systèmes, École Centrale de Lyon, Ecully Cedex 69134, France
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Reddy AB, Pilkington GA, Rutland MW, Glavatskih S. Tribotronic control of an ionic boundary layer in operando extends the limits of lubrication. Sci Rep 2022; 12:20479. [DOI: 10.1038/s41598-022-22504-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 10/17/2022] [Indexed: 11/29/2022] Open
Abstract
AbstractThe effect of electric potential on the lubrication of a non-halogenated phosphonium orthoborate ionic liquid used as an additive in a biodegradable oil was studied. An in-house tribotronic system was built around an instrument designed to measure lubricant film thickness between a rolling steel ball and a rotating silica-coated glass disc. The application of an electric field between the steel ball and a set of customized counter-electrodes clearly induced changes in the thickness of the lubricant film: a marked decrease at negative potentials and an increase at positive potentials. Complementary neutron reflectivity studies demonstrated the intrinsic electroresponsivity of the adsorbate: this was performed on a gold-coated silicon block and made possible in the same lubricant system by deuterating the oil. The results indicate that the anions, acting as anchors for the adsorbed film on the steel surface, are instrumental in the formation of thick and robust lubricating ionic boundary films. The application of a high positive potential, outside the electrochemical window, resulted in an enormous boost to film thickness, implicating the formation of ionic multi-layers and demonstrating the plausibility of remote control of failing contacts in inaccessible machinery, such as offshore wind and wave power installations.
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Self-assembled nanostructure induced in deep eutectic solvents via an amphiphilic hydrogen bond donor. J Colloid Interface Sci 2022; 616:121-128. [DOI: 10.1016/j.jcis.2022.02.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/01/2022] [Accepted: 02/06/2022] [Indexed: 12/19/2022]
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A Presentation of Ionic Liquids as Lubricants: Some Critical Comments. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11125677] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ionic liquids (ILs) are liquid materials at room temperature with an ionic intrinsic nature. The electrostatic interactions therefore play a pivotal role in dictating their inner structure, which is then expected to be far from the traditional pattern of classical simple liquids. Therefore, the strength of such interactions and their long-range effects are responsible for the ionic liquid high viscosity, a fact that itself suggests their possible use as lubricants. More interestingly, the possibility to establish a wide scenario of possible interactions with solid surfaces constitutes a specific added value in this use. In this framework, the ionic liquid complex molecular structure and the huge variety of possible interactions cause a complex aggregation pattern which can depend on the presence of the solid surface itself. Although there is plenty of literature focusing on the lubricant properties of ionic liquids and their applications, the aim of this contribution is, instead, to furnish to the reader a panoramic view of this exciting problematic, commenting on interesting and speculative aspects which are sometimes neglected in standard works and trying to furnish an enriched vision of the topic. The present work constitutes an easy-to-read critical point of view which tries to interact with the imagination of readers, hopefully leading to the discovery of novel aspects and interconnections and ultimately stimulating new ideas and research.
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Pilkington GA, Oleshkevych A, Pedraz P, Watanabe S, Radiom M, Reddy AB, Vorobiev A, Glavatskih S, Rutland MW. Electroresponsive structuring and friction of a non-halogenated ionic liquid in a polar solvent: effect of concentration. Phys Chem Chem Phys 2020; 22:19162-19171. [PMID: 32812565 DOI: 10.1039/d0cp02736g] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Neutron reflectivity (NR) measurements have been employed to study the interfacial structuring and composition of electroresponsive boundary layers formed by an ionic liquid (IL) lubricant at an electrified gold interface when dispersed in a polar solvent. The results reveal that both the composition and extent of the IL boundary layers intricately depend on the bulk IL concentration and the applied surface potential. At the lowest concentration (5% w/w), a preferential adsorption of the IL cation at the gold electrode is observed, which hinders the ability to electro-induce changes in the boundary layers. In contrast, at higher IL bulk concentrations (10 and 20% w/w), the NR results reveal a significantly larger concentration of the IL ions at the gold interface that exhibit significantly greater electroresponsivity, with clear changes in the layer composition and layer thickness observed for different potentials. In complementary atomic force microscopy (AFM) measurements on an electrified gold surface, such IL boundary layers are demonstrated to provide excellent friction reduction and electroactive friction (known as tribotronics). In agreement with the NR results obtained, clear concentration effects are also observed. Together such results provide valuable molecular insight into the electroactive structuring of ILs in solvent mixtures, as well as provide mechanistic understanding of their tribotronic behaviours.
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Affiliation(s)
- Georgia A Pilkington
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Anna Oleshkevych
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Patricia Pedraz
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Seiya Watanabe
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Milad Radiom
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| | - Akepati Bhaskar Reddy
- System and Component Design, Department of Machine Design, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Alexei Vorobiev
- Department of Physics and Astronomy, Division of Materials Physics, Uppsala University, Uppsala, Sweden
| | - Sergei Glavatskih
- System and Component Design, Department of Machine Design, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden and Department of Electromechanical, Systems and Metal Engineering, Ghent University, B-9052 Ghent, Belgium
| | - Mark W Rutland
- Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. and Surfaces, Processes and Formulation, RISE Research Institutes of Sweden, SE-100 44 Stockholm, Sweden
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Donato MT, Caetano F, Colaço R, Branco LC, Saramago B. Picolinium‐Based Hydrophobic Ionic Liquids as Additives to PEG200 to Lubricate Steel‐Silicon Contacts. ChemistrySelect 2020. [DOI: 10.1002/slct.202000613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mariana T. Donato
- LAQV-REQUIMTE Departamento de Química Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa Campus da Caparica 2829-516 Caparica Portugal
| | - Fernando Caetano
- Departamento de Ciências e Tecnologia Universidade Aberta R. da Escola Politécnica, 147 1269-001 Lisboa Portugal
| | - Rogério Colaço
- IDMEC-Departamento de Engenharia Mecânica Instituto Superior Técnico Universidade de Lisboa Av. Rovisco Pais 1049-001 Lisboa Portugal
| | - Luís C. Branco
- LAQV-REQUIMTE Departamento de Química Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa Campus da Caparica 2829-516 Caparica Portugal
| | - Benilde Saramago
- Centro de Química Estrutural and Departamento de Engenharia Química Instituto Superior Técnico Universidade de Lisboa Av Rovisco Pais 1049-001 Lisboa Portugal
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7
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Li H, Niemann T, Ludwig R, Atkin R. Effect of Hydrogen Bonding between Ions of Like Charge on the Boundary Layer Friction of Hydroxy-Functionalized Ionic Liquids. J Phys Chem Lett 2020; 11:3905-3910. [PMID: 32338913 DOI: 10.1021/acs.jpclett.0c00689] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Atomic force microscopy has been used to measure the lubricity of a series of ionic liquids (ILs) at mica surfaces in the boundary friction regime. A previously unreported cation bilayer structure is detected at the IL-mica interface due to the formation of H-bonds between the hydroxy-functionalized cations [(c-c) H-bonds], which enhances the ordering of the ions in the boundary layer and improves the lubrication. The strength of the cation bilayer structure is controlled by altering the strength of (c-c) H-bonding via changes in the hydroxyalkyl chain length, the cation charge polarizability, and the coordination strength of the anions. This reveals a new means of controlling IL boundary nanostructure via H-bonding between ions of the same charge, which can impact diverse applications, including surface catalysis, particle stability, electrochemistry, etc.
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Affiliation(s)
- Hua Li
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia 6009, Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Thomas Niemann
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany
- Department LL&M, University of Rostock, Albert-Einstein-Strasse 25, 18059 Rostock, Germany
| | - Ralf Ludwig
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany
- Department LL&M, University of Rostock, Albert-Einstein-Strasse 25, 18059 Rostock, Germany
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia 6009, Australia
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Khazalpour S, Yarie M, Kianpour E, Amani A, Asadabadi S, Seyf JY, Rezaeivala M, Azizian S, Zolfigol MA. Applications of phosphonium-based ionic liquids in chemical processes. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2020. [DOI: 10.1007/s13738-020-01901-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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9
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Li H, Choi YS, Rutland MW, Atkin R. Nanotribology of hydrogels with similar stiffness but different polymer and crosslinker concentrations. J Colloid Interface Sci 2020; 563:347-353. [PMID: 31887698 DOI: 10.1016/j.jcis.2019.12.045] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/02/2019] [Accepted: 12/12/2019] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS The stiffness has been found to regulate hydrogel performances and applications. However, the key interfacial properties of hydrogels, like friction and adhesion are not controlled by the stiffness, but are altered by the structure and composition of hydrogels, like polymer volume fraction and crosslinking degree. EXPERIMENTS Colloidal probe atomic force microscopy has been use to investigate the relationship between tribological properties (friction and adhesion) and composition of hydrogels with similar stiffness, but different polymer volume fractions and crosslinking degrees. FINDINGS The interfacial normal and lateral (friction) forces of hydrogels are not directly correlated to the stiffness, but altered by the hydrogel structure and composition. For normal force measurements, the adhesion increases with polymer volume fraction but decreases with crosslinking degree. For lateral force measurements, friction increases with polymer volume fraction, but decreases with crosslinking degree. In the low normal force regime, friction is mainly adhesion-controlled and increases significantly with the adhesion and polymer volume fraction. In the high normal force regime, friction is predominantly load-controlled and shows slow increase with normal force.
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Affiliation(s)
- Hua Li
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia; Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA 6009, Australia.
| | - Yu Suk Choi
- School of Human Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Mark W Rutland
- School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE100 44, Sweden; Surfaces, Processes and Formulation, RISE Research Institutes of Sweden, SE114 86 Stockholm, Sweden
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
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10
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Hjalmarsson N, Bergendal E, Wang YL, Munavirov B, Wallinder D, Glavatskih S, Aastrup T, Atkin R, Furó I, Rutland MW. Electro-Responsive Surface Composition and Kinetics of an Ionic Liquid in a Polar Oil. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15692-15700. [PMID: 31581771 DOI: 10.1021/acs.langmuir.9b02119] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The quartz crystal microbalance (QCM) has been used to study how the interfacial layer of an ionic liquid dissolved in a polar oil at low weight percentages responds to changes in applied potential. The changes in surface composition at the QCM gold surface depend on both the magnitude and sign of the applied potential. The time-resolved response indicates that the relaxation kinetics are limited by the diffusion of ions in the interfacial region and not in the bulk, since there is no concentration dependence. The measured mass changes cannot be explained only in terms of simple ion exchange; the relative molecular volumes of the ions and the density changes in response to ion exclusion must be considered. The relaxation behavior of the potential between the electrodes upon disconnecting the applied potential is more complex than that observed for pure ionic liquids, but a measure of the surface charge can be extracted from the exponential decay when the rapid initial potential drop is accounted for. The adsorbed film at the gold surface consists predominantly of ionic liquid despite the low concentration, which is unsurprising given the surtactant-like structures of (some of) the ionic liquid ions. Changes in response to potential correspond to changes in the relative numbers of cations and anions, rather than a change in the oil composition. No evidence for an electric field induced change in viscosity is observed. This work shows conclusively that electric potentials can be used to control the surface composition, even in an oil-based system, and paves the way for other ion solvent studies.
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Affiliation(s)
| | | | | | | | | | - Sergei Glavatskih
- Department of Electrical Energy, Metals, Mechanical Constructions and Systems , Ghent University , B-9000 , Ghent , Belgium
| | | | - Rob Atkin
- School of Molecular Sciences , University of Western Australia , 6009 Perth , Australia
| | | | - Mark W Rutland
- Surfaces, Processes and Formulation , RISE Research Institutes of Sweden , SE-50115 Stockholm , Sweden
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11
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Cooper PK, Staddon J, Zhang S, Aman ZM, Atkin R, Li H. Nano- and Macroscale Study of the Lubrication of Titania Using Pure and Diluted Ionic Liquids. Front Chem 2019; 7:287. [PMID: 31106198 PMCID: PMC6498968 DOI: 10.3389/fchem.2019.00287] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 04/08/2019] [Indexed: 11/13/2022] Open
Abstract
Titanium is a strong, corrosion-resistant light-weight metal which is poised to replace steel in automobiles, aircraft, and watercraft. However, the titanium oxide (titania) layer that forms on the surface of titanium in air is notoriously difficult to lubricate with conventional lubricants, which restricts its use in moving parts such as bearings. Ionic liquids (ILs) are potentially excellent lubricants for titania but the relationship between IL molecular structure and lubricity for titania remains poorly understood. Here, three-ball-on-disk macrotribology and atomic force microscopy (AFM) nanotribology measurements reveal the lubricity of four IL lubricants: trioctyl(2-ethylhexyl)phosphonium bis(2-ethylhexyl)phosphate (P8,8,8,6(2) BEHP), trihexyl(tetradecyl)phosphonium bis(2-ethylhexyl)phosphate (P6,6,6,14 BEHP), trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (P6,6,6,14 ( i C8)2PO2), and trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide (P6,6,6,14 TFSI). The macrotribology measurements demonstrated that friction decreased in P6,6,6,14 TFSI by four times (μ = 0.13) compared to in hexadecane, even at 60°C and loads up to 10 N. On the other hand, P8,8,8,6(2) BEHP reduced friction most effectively in the AFM nanotribology measurements. The results were interpreted in terms of the lubrication regime. The lower viscosity of P6,6,6,14 TFSI coupled with its good boundary lubrication made it the most effective IL for the macrotribology measurements, which were in the mixed lubrication regime. Conversely, the cation structure of P8,8,8,6(2) BEHP allowed it to adsorb strongly to the surface and minimized energy dissipation in the nanotribology measurements, although its high bulk viscosity inhibited its performance in the mixed regime. These results reinforce the importance of carefully selecting IL lubricants based on the lubrication regime of the sliding surfaces.
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Affiliation(s)
- Peter K Cooper
- School of Molecular Sciences, University of Western Australia, Crawley, WA, Australia
| | - Joe Staddon
- School of Molecular Sciences, University of Western Australia, Crawley, WA, Australia
| | - Songwei Zhang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China
| | - Zachary M Aman
- Fluid Science and Resources, Department of Chemical Engineering, University of Western Australia, Crawley, WA, Australia
| | - Rob Atkin
- School of Molecular Sciences, University of Western Australia, Crawley, WA, Australia
| | - Hua Li
- School of Molecular Sciences, University of Western Australia, Crawley, WA, Australia
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12
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Dou J, Zhao Y, Yin F, Li H, Yu J. Mechanistic Study of Selective Absorption of NO in Flue Gas Using EG-TBAB Deep Eutectic Solvents. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:1031-1038. [PMID: 30540453 DOI: 10.1021/acs.est.8b05408] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The selective absorption of NO in flue gas has been investigated using a series of deep eutectic solvents (DESs) as novel denitrifying agents. The EG-TBAB DESs used in this work are composed of a hydrogen donor ethylene glycol (EG) and a parent salt tetrabutylammonium bromide (TBAB). Effects of DES composition (EG:TBAB molar ratio), operation temperature, residence time, and O2 concentration in the flue gas on denitrification performances of EG-TBAB DESs have been investigated. The highest denitrification efficiency and capacity were achieved using EG to TBAB molar ratio of 50:1 at an operation temperature of 50 °C. The O2 partial pressure in the flue gas showed no noticeable effects on NO absorption in EG-TBAB DESs. EG-TBAB DESs maintain high denitrification stability after five absorption-desorption cycles. The calculated absorption equilibrium constant ( K0) and Henry's law constant ( H) showed that EG-TBAB DESs exhibited high absorption capacity for NO molecules, indicating that they are applicable in industrial denitrification processes. The kinetics analysis of NO absorption in EG-TBAB DESs indicated that EG-TBAB DESs could effectively absorb NO and the absorption of NO was strongly influenced by mass transfer.
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Affiliation(s)
- Jinxiao Dou
- Key Laboratory for Advanced Coal and Coking Technology of Liaoning Province, School of Chemical Engineering , University of Science and Technology Liaoning , Anshan 114051 , China
| | - Yongqi Zhao
- Key Laboratory for Advanced Coal and Coking Technology of Liaoning Province, School of Chemical Engineering , University of Science and Technology Liaoning , Anshan 114051 , China
| | - Fengkui Yin
- Key Laboratory for Advanced Coal and Coking Technology of Liaoning Province, School of Chemical Engineering , University of Science and Technology Liaoning , Anshan 114051 , China
- Chemical Engineering , University of Newcastle , Callaghan , New South Wales 2308 , Australia
| | - Hua Li
- Key Laboratory for Advanced Coal and Coking Technology of Liaoning Province, School of Chemical Engineering , University of Science and Technology Liaoning , Anshan 114051 , China
- School of Molecular Sciences , University of Western Australia , Crawley , Western Australia 6009 , Australia
| | - Jianglong Yu
- Key Laboratory for Advanced Coal and Coking Technology of Liaoning Province, School of Chemical Engineering , University of Science and Technology Liaoning , Anshan 114051 , China
- Chemical Engineering , University of Newcastle , Callaghan , New South Wales 2308 , Australia
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13
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Gong X, Wang B, Li L. Spreading of Nanodroplets of Ionic Liquids on the Mica Surface. ACS OMEGA 2018; 3:16398-16402. [PMID: 31458275 PMCID: PMC6643696 DOI: 10.1021/acsomega.8b02423] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 11/22/2018] [Indexed: 06/01/2023]
Abstract
Previously, the molecular structure of ionic liquids (ILs) next to a solid surface has been extensively studied because the IL-solid interfaces are critical to many important applications. What is largely unknown is the mobility of ILs confined to a solid surface. The solid-like stable structure of ILs on the solid surfaces has been reported in previous research, which indicates that the mobility of ILs next to a solid surface is quite low and the structure of ILs will not change with time. However, here, we show that the nanodroplets of ILs flow on the mica surface, which suggest that, at a small scale, the solid-like stable structure of ILs on the solid surfaces indeed changes with time. Interestingly, although the IL nanodroplets show a layered structure, no terrace-like flow of the droplet has been observed, which has been attributed to the weak mica-IL interaction at low humidity.
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Affiliation(s)
- Xiao Gong
- State
Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China
- Department
of Chemical & Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Bingchen Wang
- Department
of Chemical & Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Lei Li
- Department
of Chemical & Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
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Pilkington GA, Harris K, Bergendal E, Reddy AB, Palsson GK, Vorobiev A, Antzutkin ON, Glavatskih S, Rutland MW. Electro-responsivity of ionic liquid boundary layers in a polar solvent revealed by neutron reflectance. J Chem Phys 2018; 148:193806. [DOI: 10.1063/1.5001551] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Georgia A. Pilkington
- Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Kathryn Harris
- System and Component Design, Department of Machine Design, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Erik Bergendal
- Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Akepati Bhaskar Reddy
- System and Component Design, Department of Machine Design, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Gunnar K. Palsson
- Department of Physics and Astronomy, Division of Materials Physics, Uppsala University, Uppsala, Sweden
| | - Alexei Vorobiev
- Department of Physics and Astronomy, Division of Materials Physics, Uppsala University, Uppsala, Sweden
| | | | - Sergei Glavatskih
- System and Component Design, Department of Machine Design, KTH Royal Institute of Technology, Stockholm, Sweden
- Department of Electrical Energy, Systems and Automation, Ghent University, Ghent, Belgium
| | - Mark W. Rutland
- Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden
- Surfaces, Processes and Formulation, RISE Research Institutes of Sweden, Stockholm, Sweden
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15
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Highly selective adsorption of hydroquinone by hydroxyethyl cellulose functionalized with magnetic/ionic liquid. Int J Biol Macromol 2017; 107:957-964. [PMID: 28939516 DOI: 10.1016/j.ijbiomac.2017.09.075] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 09/09/2017] [Accepted: 09/18/2017] [Indexed: 01/06/2023]
Abstract
Magnetic hydroxyethyl cellulose/ionic liquid (MHEC/IL) materials were fabricated through a facile and fast process and their application as excellent adsorbents for hydroquinone was also demonstrated. The thermal stability, chemical structure and magnetic property of the MHEC/IL were characterized by the Scanning electron microscope (SEM), Transmission Electron Microscope (TEM), Fourier transform infrared spectrometer (FT-IR) and X-ray diffraction (XRD), respectively. The adsorbents were used for the removal of hydroquinone from simulated wastewater with a fast solid-liquid separation in the presence of external magnetic field. The influence of various analytical parameters on the adsorption of hydroquinone such as pH, contact time and initial ion concentration were studied in detail. The results showed that the maximum adsorption capacity was 335.68mgg-1, observed at pH 5 and temperature 30°C. Equilibrium adsorption was achieved within 30min. The kinetic data, obtained at the optimum pH 5, could be fitted with a pseudo-second order equation. Adsorption process could be well described by Freundlich adsorption isotherms. The obtained results indicated that the impregnation of the room temperature IL significantly enhances the removal efficiency of hydroquinone. The MHEC/IL may be suitable materials in phenols pollution cleanup if they are synthesized in largescale and at low price in near future.
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Amorim PM, Ferraria AM, Colaço R, Branco LC, Saramago B. Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:1961-1971. [PMID: 29046844 PMCID: PMC5629412 DOI: 10.3762/bjnano.8.197] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 08/31/2017] [Indexed: 06/02/2023]
Abstract
In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS), the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs) as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG) to lubricate Si surfaces. The friction coefficients were measured in a nanotribometer. The viscosity of the PEG + IL mixtures as well as their contact angles on the Si surface were measured. The topography and chemical composition of the substrates surfaces were determined with atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. Due to the hygroscopic properties of PEG, the first step was to assess the effect of the presence of water. Then, a series of ILs based on the cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-ethyl-3-vinylimidazolium [EVIM], 1-(2-hydroxyethyl)-3-methylimidazolium [C2OHMIM] and 1-allyl-3-methylimidazolium [AMIM] combined with the anions dicyanamide [DCA], trifluoromethanesulfonate [TfO], and ethylsulfate [EtSO4] were added to dry PEG. All additives (2 wt %) led to a decrease in friction coefficient as well as an increase in viscosity (with the exception of [AMIM][TfO]) and improved the Si wettability. The additives based on the anion [EtSO4] exhibited the most promising tribological behavior, which was attributed to the strong interaction with the Si surface ensuring the formation of a stable surface layer, which hinders the contact between the sliding surfaces.
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Affiliation(s)
- Patrícia M Amorim
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- LAQV-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal
| | - Ana M Ferraria
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Rogério Colaço
- IDMEC-Instituto de Engenharia Mecânica, Departamento de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Luís C Branco
- LAQV-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal
| | - Benilde Saramago
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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17
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18
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Wang YL, Golets M, Li B, Sarman S, Laaksonen A. Interfacial Structures of Trihexyltetradecylphosphonium-bis(mandelato)borate Ionic Liquid Confined between Gold Electrodes. ACS APPLIED MATERIALS & INTERFACES 2017; 9:4976-4987. [PMID: 28099800 DOI: 10.1021/acsami.6b14429] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Atomistic molecular dynamics simulations have been performed to study microscopic the interfacial ionic structures, molecular arrangements, and orientational preferences of trihexyltetradecylphosphonium-bis(mandelato)borate ([P6,6,6,14][BMB]) ionic liquid confined between neutral and charged gold electrodes. It was found that both [P6,6,6,14] cations and [BMB] anions are coabsorbed onto neutral electrodes at different temperatures. The hexyl and tetradecyl chains in [P6,6,6,14] cations lie preferentially flat on neutral electrodes. The oxalato and phenyl rings in [BMB] anions are characterized by alternative parallel-perpendicular orientations in the mixed innermost ionic layer adjacent to neutral electrodes. An increase in temperature has a marginal effect on the interfacial ionic structures and molecular orientations of [P6,6,6,14][BMB] ionic species in a confined environment. Electrifying gold electrodes leads to peculiar changes in the interfacial ionic structures and molecular orientational arrangements of [P6,6,6,14] cations and [BMB] anions in negatively and positively charged gold electrodes, respectively. As surface charge density increases (but lower than 20 μC/cm2), the layer thickness of the mixed innermost interfacial layer gradually increases due to a consecutive accumulation of [P6,6,6,14] cations and [BMB] anions at negatively and positively charged electrodes, respectively, before the formation of distinct cationic and anionic innermost layers. Meanwhile, the molecular orientations of two oxalato rings in the same [BMB] anions change gradually from a parallel-perpendicular feature to being partially characterized by a tilted arrangement at an angle of 45° from the electrodes and finally to a dominant parallel coordination pattern along positively charged electrodes. Distinctive interfacial distribution patterns are also observed accordingly for phenyl rings that are directly connected to neighboring oxalato rings in [BMB] anions.
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Affiliation(s)
- Yong-Lei Wang
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91 Stockholm, Sweden
| | - Mikhail Golets
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91 Stockholm, Sweden
| | - Bin Li
- Theoretical Chemistry, Chemical Center, Lund University , P.O. Box 124, SE-221 00 Lund, Sweden
| | - Sten Sarman
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91 Stockholm, Sweden
| | - Aatto Laaksonen
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91 Stockholm, Sweden
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19
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Zhou Y, Qu J. Ionic Liquids as Lubricant Additives: A Review. ACS APPLIED MATERIALS & INTERFACES 2017; 9:3209-3222. [PMID: 28029771 DOI: 10.1021/acsami.6b12489] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In pursuit of energy efficiency and durability throughout human history, advances in lubricants have always played important roles. Ionic liquids (ILs) are room-temperature molten salts that possess unique physicochemical properties and have shown great potential in many applications with lubrication as one of the latest. While earlier work (2001-2011) primarily explored the feasibility of using ILs as neat or base lubricants, using ILs as lubricant additives has become the new focal research topic since the breakthrough in ILs' miscibility in nonpolar hydrocarbon oils in early 2012. This work reviews the recent advances in developing ILs as additives for lubrication with an attempt to correlate among the cationic and anionic structures, oil-solubility, and other relevant physicochemical properties, and lubricating behavior. Effects of the concentration of ILs in lubricants and the compatibility between ILs and other additives in the lubricant formulation on the tribological performance are described followed by a discussion of wear protection mechanism based on tribofilm characterization. Future research directions are suggested at the end.
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Affiliation(s)
- Yan Zhou
- Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37830, United States
| | - Jun Qu
- Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37830, United States
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20
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Ploss MA, Rutland MW, Glavatskih S. Influence of electric potential on the apparent viscosity of an ionic liquid: facts and artifacts. Phys Chem Chem Phys 2016; 18:26609-26615. [PMID: 27711405 DOI: 10.1039/c6cp02846b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
According to recent findings, the steady shear viscosity of the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][Tf2N]) decreases significantly under the influence of electric potential. This implies a causal connection between nanoscale ordering at the electrified interface and a macroscopic change of transport properties. To study this phenomenon in more detail, we reproduced the above-mentioned measurements; however, we find no evidence that the viscosity of [Emim][Tf2N] is a function of electric potential. Additionally, our results show that steady shear measurements can lead to artifacts that, at first glance, may appear to be potential-induced changes in viscosity. We demonstrate that the artifacts result from a sliding electrical contact at the working electrode of the electrochemical cell and we suggest to consider our findings for future viscosity measurements of ionic liquids.
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Affiliation(s)
- Moritz A Ploss
- System and Component Design, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Mark W Rutland
- Surface and Corrosion Science, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. and Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden
| | - Sergei Glavatskih
- System and Component Design, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden and Mechanical Construction and Production, Ghent University, B-9000 Ghent, Belgium
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21
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Sweeney J, Webber GB, Atkin R. Poly(ethylene oxide) Mushrooms Adsorbed at Silica-Ionic Liquid Interfaces Reduce Friction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:1947-1954. [PMID: 26844589 DOI: 10.1021/acs.langmuir.5b04503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The adsorbed layer conformation and lubricity of 35, 100, and 300 kDa PEO adsorbed to ionic liquid (IL)-silica interfaces from 0.01 wt % solutions have been investigated using colloid probe atomic force microscopy. The ILs used were propylammonium nitrate (PAN) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), which are protic and aprotic ILs, respectively. Normal force curves reveal steric interactions consistent with adsorbed polymer layers which are best fit using the mushroom model. Friction measurements show that the adsorbed polymer layer markedly reduces friction compared to surfaces sliding in the pure ILs and that lubricity increases with polymer length. When polymer is adsorbed to the sliding surfaces, friction is controlled by the creation and disruption of intermolecular interactions between entangled chains and the dragging of polymer chains through the interpenetration region. These experiments show that added polymer can reduce friction while maintaining the useful properties of ILs as lubricants.
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Affiliation(s)
- James Sweeney
- Priority Research Centre for Advanced Fluids and Interfaces, Newcastle Institute for Energy and Resources, The University of Newcastle , Callaghan, NSW 2308, Australia
| | - Grant B Webber
- Priority Research Centre for Advanced Fluids and Interfaces, Newcastle Institute for Energy and Resources, The University of Newcastle , Callaghan, NSW 2308, Australia
| | - Rob Atkin
- Priority Research Centre for Advanced Fluids and Interfaces, Newcastle Institute for Energy and Resources, The University of Newcastle , Callaghan, NSW 2308, Australia
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22
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McDonald S, Elbourne A, Warr GG, Atkin R. Metal ion adsorption at the ionic liquid-mica interface. NANOSCALE 2016; 8:906-914. [PMID: 26661934 DOI: 10.1039/c5nr05833c] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mica has been employed in many studies of ionic liquid (IL) interfaces on account of its atomic smoothness and well defined surface properties. However, until now it has been unclear whether ions dissolved in ILs can compete with the IL cation and adsorb to mica charge sites. In this work amplitude modulated atomic force microscopy (AM-AFM) has been used to probe metal ion adsorption at the interface of mica with propylammonium nitrate (PAN), a room temperature IL. Lithium, sodium, potassium, magnesium and calcium nitrate salts were added to PAN at a concentration of ∼60 mM. Aluminum nitrate was also investigated, but only at 5 mM because its solubility in PAN is much lower. The AM-AFM images obtained when the metal ions were present are strikingly different to that of pure PAN, indicating that the ions compete effectively with the propylammonium cation and adsorb to negatively charged sites on the mica surface despite their much lower concentration. This is a consequence of electrostatic attractions between the mica charge sites and the metal ions being significantly stronger than for the propylammonium cation; compared to the metal ions the propylammonium charged group is relatively constrained sterically. A distinct honeycomb pattern is noted for the PAN + Al(3+) system, less obviously for the divalent ions and not at all for monovalent ions. This difference is attributed to the strength of electrostatic interactions between metal ions and mica charge sites increasing with the ion charge, which means that divalent and (particularly) trivalent ions are located more precisely above the charged sites of the mica lattice. The images obtained allow important distinctions between metal ion adsorption at mica-water and mica-PAN interfaces to be made.
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Affiliation(s)
- Samila McDonald
- Discipline of Chemistry, The Newcastle Institute for Energy and Resources, The University of Newcastle, Newcastle, NSW, Australia.
| | - Aaron Elbourne
- Discipline of Chemistry, The Newcastle Institute for Energy and Resources, The University of Newcastle, Newcastle, NSW, Australia.
| | - Gregory G Warr
- School of Chemistry, University of Sydney, Sydney, NSW, Australia
| | - Rob Atkin
- Discipline of Chemistry, The Newcastle Institute for Energy and Resources, The University of Newcastle, Newcastle, NSW, Australia.
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23
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Cooper PK, Li H, Rutland MW, Webber GB, Atkin R. Tribotronic control of friction in oil-based lubricants with ionic liquid additives. Phys Chem Chem Phys 2016; 18:23657-62. [PMID: 27511143 DOI: 10.1039/c6cp04405k] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Atomic force microscopy (AFM) reveals that tribotronic control of friction using an external potential applied to a gold surface is possible for ionic liquid (IL) concentrations as low as 5 mol% in hexadecane.
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Affiliation(s)
- P. K. Cooper
- Priority Research Centre for Advanced Fluids and Interfaces
- Newcastle Institute for Energy and Resources
- University of Newcastle
- Callaghan
- Australia
| | - H. Li
- Priority Research Centre for Advanced Fluids and Interfaces
- Newcastle Institute for Energy and Resources
- University of Newcastle
- Callaghan
- Australia
| | - M. W. Rutland
- KTH Royal Institute of Technology
- School of Chemical Science and Engineering
- Department of Chemistry
- SE-100 44 Stockholm
- Sweden
| | - G. B. Webber
- Priority Research Centre for Advanced Fluids and Interfaces
- Newcastle Institute for Energy and Resources
- University of Newcastle
- Callaghan
- Australia
| | - R. Atkin
- Priority Research Centre for Advanced Fluids and Interfaces
- Newcastle Institute for Energy and Resources
- University of Newcastle
- Callaghan
- Australia
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24
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Murphy T, Callear SK, Warr GG, Atkin R. Dissolved chloride markedly changes the nanostructure of the protic ionic liquids propylammonium and ethanolammonium nitrate. Phys Chem Chem Phys 2016; 18:17169-82. [DOI: 10.1039/c5cp06947e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bulk nanostructure of 15 mol% propylammonium chloride (PACl) dissolved in propylammonium nitrate (PAN) and 15 mol% ethanolammonium chloride (EtACl) in ethanolammonium nitrate (EtAN) has been determined using neutron diffraction with empirical potential structure refinement fits.
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Affiliation(s)
- Thomas Murphy
- Priority Research Centre for Advanced Fluids and Interfaces
- The University of Newcastle
- Callaghan
- Australia
| | | | | | - Rob Atkin
- Priority Research Centre for Advanced Fluids and Interfaces
- The University of Newcastle
- Callaghan
- Australia
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25
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Li H, Somers AE, Howlett PC, Rutland MW, Forsyth M, Atkin R. Addition of low concentrations of an ionic liquid to a base oil reduces friction over multiple length scales: a combined nano- and macrotribology investigation. Phys Chem Chem Phys 2016; 18:6541-7. [DOI: 10.1039/c5cp07061a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The efficacy of ionic liquids (ILs) as lubricant additives to a model base oil has been probed at the nanoscale and macroscale as a function of IL concentration using the same materials.
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Affiliation(s)
- Hua Li
- Priority Research Centre for Advanced Fluids and Interfaces
- The University of Newcastle
- Callaghan
- Australia
| | | | | | - Mark W. Rutland
- School of Chemical Science and Engineering
- KTH Royal Institute of Technology
- SE100 44, Sweden
- Chemistry
- Materials and Surfaces
| | - Maria Forsyth
- Institute for Frontier Materials
- Deakin University
- Geelong
- Australia
| | - Rob Atkin
- Priority Research Centre for Advanced Fluids and Interfaces
- The University of Newcastle
- Callaghan
- Australia
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26
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Affiliation(s)
- Robert Hayes
- Discipline
of Chemistry, The University of Newcastle, NSW 2308, Callaghan, Australia
| | - Gregory G. Warr
- School
of Chemistry, The University of Sydney, NSW 2006, Sydney, Australia
| | - Rob Atkin
- Discipline
of Chemistry, The University of Newcastle, NSW 2308, Callaghan, Australia
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27
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Wydro MJ, Warr GG, Atkin R. Amplitude-modulated atomic force microscopy reveals the near surface nanostructure of surfactant sponge (L(3)) and lamellar (L(α)) phases. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:5513-5520. [PMID: 25906083 DOI: 10.1021/acs.langmuir.5b01008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Amplitude-modulated atomic force microscopy (AM-AFM) has been used to study the nanostructure of cetylpyridinium chloride (CPCl)-hexanol-0.2 M NaCl sponge (L3) and lamellar (Lα) phases near a mica surface. For both phases, membrane volume fractions of 22, 27, and 32 vol % were investigated, with the L3 or Lα phase selected by adjusting the co-surfactant/surfactant ratio (hexanol/CPCl). For the L3 phase, the presence of the surface flattens the three-dimensional bulk structure. AM-AFM clearly resolves the membrane and solvent passages in the near surface layer. Increasing the membrane volume fraction decreases the size of the image features because of the lower solvent content. Within error, the average passage sizes in the near surface layer are the same as those in the bulk at the same concentration. Images of the Lα phase reveal undulating near surface sheets. At the highest membrane concentration, the image is very smooth, because the lamellar sheet is confined between the surface and the next near surface layer, which is in close proximity as a result of the low solvent content. As the membrane concentration is reduced, the space between layers is increased and undulations appear in the near surface lamellar structure. Undulations are more pronounced at the lowest membrane volume fraction.
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Affiliation(s)
- Marc J Wydro
- †University of Newcastle, Newcastle, New South Wales 2308, Australia
| | - Gregory G Warr
- ‡University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rob Atkin
- †University of Newcastle, Newcastle, New South Wales 2308, Australia
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28
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Sweeney J, Webber GB, Atkin R. Near surface properties of mixtures of propylammonium nitrate with n-alkanols 2. Nanotribology and fluid dynamics. Phys Chem Chem Phys 2015; 17:26629-37. [DOI: 10.1039/c5cp04787k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Colloid probe friction force microscopy (FFM) has been used to study the lubricity of propylammonium nitrate (PAN) mixed with n-alkanols confined between sliding silica and mica surfaces.
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Affiliation(s)
- James Sweeney
- Centre for Advanced Particle Processing and Transport
- Newcastle Institute for Energy and Resources
- The University of Newcastle
- Callaghan
- Australia
| | - Grant B. Webber
- Centre for Advanced Particle Processing and Transport
- Newcastle Institute for Energy and Resources
- The University of Newcastle
- Callaghan
- Australia
| | - Rob Atkin
- Centre for Advanced Particle Processing and Transport
- Newcastle Institute for Energy and Resources
- The University of Newcastle
- Callaghan
- Australia
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29
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Wang YL, Sarman S, Li B, Laaksonen A. Multiscale modeling of the trihexyltetradecylphosphonium chloride ionic liquid. Phys Chem Chem Phys 2015; 17:22125-35. [DOI: 10.1039/c5cp02586a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hierarchical trihexyltetradecylphosphonium cationic and chloride anionic models.
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Affiliation(s)
- Yong-Lei Wang
- System and Component Design
- Department of Machine Design
- KTH Royal Institute of Technology
- SE-100 44 Stockholm
- Sweden
| | - Sten Sarman
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Bin Li
- Theoretical Chemistry
- Chemical Center
- Lund University
- SE-221 00 Lund
- Sweden
| | - Aatto Laaksonen
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
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30
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Li H, Atkin R, Page AJ. Combined friction force microscopy and quantum chemical investigation of the tribotronic response at the propylammonium nitrate–graphite interface. Phys Chem Chem Phys 2015; 17:16047-52. [DOI: 10.1039/c5cp01952d] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The energetic origins of the variation in friction with potential at the propylammonium nitrate–graphite interface are revealed using friction force microscopy (FFM) in combination with quantum chemical simulations.
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Affiliation(s)
- H. Li
- Newcastle Institute for Energy and Resources
- The University of Newcastle
- Callaghan
- Australia
| | - R. Atkin
- Newcastle Institute for Energy and Resources
- The University of Newcastle
- Callaghan
- Australia
| | - A. J. Page
- Newcastle Institute for Energy and Resources
- The University of Newcastle
- Callaghan
- Australia
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