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Li H, Wang J, Warr GG, Atkin R. Effect of Potential on the Nanostructure Dynamics of Ethylammonium Nitrate at a Graphite Electrode. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2306011. [PMID: 37806754 DOI: 10.1002/smll.202306011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/20/2023] [Indexed: 10/10/2023]
Abstract
Video-rate atomic force microscopy (AFM) is used to study the near-surface nanostructure dynamics of the ionic liquid ethylammonium nitrate (EAN) at a highly oriented pyrolytic graphite (HOPG) electrode as a function of potential in real-time for the first time. The effects of varying the surface potential and adding 10 wt% water on the nanostructure diffusion coefficient are probed. For both EAN and the 90 wt% EAN-water mixture, disk-like features ≈9 nm in diameter and 1 nm in height form above the Stern layer at all potentials. The nanostructure diffusion coefficient increases with potential (from OCP -0.5 V to OCP +0.5 V) and with added water. Nanostructure dynamics depends on both the magnitude and direction of the potential change. Upon switching the potential from OCP -0.5 V to OCP +0.5 V, a substantial increase in the diffusion coefficients is observed, likely due to the absence of solvophobic interactions between the nitrate (NO3 - ) anions and the ethylammonium (EA+ ) cations in the near-surface region. When the potential is reversed, EA+ is attracted to the Stern layer to replace NO3 - , but its movement is hindered by solvophobic attractions. The outcomes will aid applications, including electrochemical devices, catalysts, and lubricants.
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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
| | - Jianan Wang
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Gregory G Warr
- School of Chemistry and Sydney Nano Institute, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia, 6009, Australia
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2
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Fiuza T, Sarkar M, Riedl JC, Beaughon M, Torres Bautista BE, Bhattacharya K, Cousin F, Barruet E, Demouchy G, Depeyrot J, Dubois E, Gélébart F, Geertsen V, Mériguet G, Michot L, Nakamae S, Perzynski R, Peyre V. Ion specific tuning of nanoparticle dispersion in an ionic liquid: a structural, thermoelectric and thermo-diffusive investigation. Phys Chem Chem Phys 2023; 25:28911-28924. [PMID: 37855156 DOI: 10.1039/d3cp02399k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Dispersions of charged maghemite nanoparticles (NPs) in EAN (ethylammonium nitrate) a reference Ionic Liquid (IL) are studied here using a number of static and dynamical experimental techniques; small angle scattering (SAS) of X-rays and of neutrons, dynamical light scattering and forced Rayleigh scattering. Particular insight is provided regarding the importance of tuning the ionic species present at the NP/IL interface. In this work we compare the effect of Li+, Na+ or Rb+ ions. Here, the nature of these species has a clear influence on the short-range spatial organisation of the ions at the interface and thus on the colloidal stability of the dispersions, governing both the NP/NP and NP/IL interactions, which are both evaluated here. The overall NP/NP interaction is either attractive or repulsive. It is characterised by determining, thanks to the SAS techniques, the second virial coefficient A2, which is found to be independent of temperature. The NP/IL interaction is featured by the dynamical effective charge ξeff0 of the NPs and by their entropy of transfer ŜNP (or equivalently their heat of transport ) determined here thanks to thermoelectric and thermodiffusive measurements. For repulsive systems, an activated process rules the temperature dependence of these two latter quantities.
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Affiliation(s)
- T Fiuza
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
- Grupo de Fluidos Complexos, Inst. de Fisíca, Univ. de Brasília, Brasília (DF), Brazil
| | - M Sarkar
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - J C Riedl
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - M Beaughon
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - B E Torres Bautista
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - K Bhattacharya
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - F Cousin
- Lab. Léon Brillouin-UMR 12 CNRS-CEA CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - E Barruet
- Univ. Paris-Saclay, CEA, CNRS, NIMBE-LIONS, 91191 Gif sur Yvette, CEDEX, France
| | - G Demouchy
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
- Univ. de Cergy Pontoise-Dpt de physique, 33 Bd du Port, 95011 Cergy-Pontoise, France
| | - J Depeyrot
- Grupo de Fluidos Complexos, Inst. de Fisíca, Univ. de Brasília, Brasília (DF), Brazil
| | - E Dubois
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - F Gélébart
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - V Geertsen
- Univ. Paris-Saclay, CEA, CNRS, NIMBE-LIONS, 91191 Gif sur Yvette, CEDEX, France
| | - G Mériguet
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - L Michot
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - S Nakamae
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - R Perzynski
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - V Peyre
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
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3
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Filippov A, Antzutkin ON. State of anion in ethylammonium nitrate enclosed between micrometer-spaced glass plates as studied by 17O and 15N NMR. Phys Chem Chem Phys 2023; 25:14538-14545. [PMID: 37191082 DOI: 10.1039/d3cp01737k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Some aprotic and protic ionic liquids (ILs) containing nitrate anion demonstrate unusual dynamic behavior of cations when these ILs are enclosed in micrometer-spaced layers between glass plates. We applied 17O and 15N NMR spectroscopy to discover the state and transformations of 17O and 15N isotopically enriched nitrate anion of ethylammonium nitrate (EAN) enclosed between glass plates. 15N NMR spectra demonstrated preferential orientation of the principal axes of the nitrate anions perpendicular to the normal of the glass surface. Therefore, isotropic ionic liquid EAN, when placed within a micrometer-spaced enclosure, forms an ordered phase, which is similar to a liquid crystal. The peculiarity of this phase is that the cations do not have a predominant orientation. Other features of this phase that are typical for liquid crystal phases are the changed local and translational dynamics in comparison with the isotropic state and slow transformation occurring under the action of an external magnetic field.
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Affiliation(s)
- Andrei Filippov
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden.
| | - Oleg N Antzutkin
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden.
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4
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Li H, Wang J, Warr GG, Atkin R. Extremely slow dynamics of ionic liquid self-assembled nanostructures near a solid surface. J Colloid Interface Sci 2023; 630:658-665. [DOI: 10.1016/j.jcis.2022.10.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/20/2022] [Accepted: 10/23/2022] [Indexed: 11/06/2022]
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5
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Sedov IA, Magsumov TI. Highlighting the difference in nanostructure between domain-forming and domainless protic ionic liquids. Phys Chem Chem Phys 2022; 24:21477-21494. [PMID: 36053503 DOI: 10.1039/d2cp02925a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nanoheterogeneity in some ionic liquids is a known phenomenon, but quantifying or sometimes even identifying it is not a straightforward task. We compared several known and suggested some novel approaches to identify and characterize domain segregation using the results of atomistic simulations. 10 ammonium-based protic ionic liquids with different propensity to form segregated polar and apolar domains as suggested by experimental studies were considered. They include butyl-, propyl-, 2-methoxyethylammonium nitrate, butyl- and propylammonium hydrogen sulfate, butylammonium thiocyanate (domain-forming liquids), ethylammonium and pyrrolidinium nitrate (weakly pronounced segregation), methylammonium and 2-hydroxyethylammonium nitrate (domainless liquids). Molecular dynamics simulations were performed using models based on the OPLS-AA force field with scaled ion charges. Results show that domains can be recognized and the characteristic domain length scale can be determined from peaks of Ripley's functions, peaks and large-period oscillations of finite-volume radial distribution function integral, or difference of such integrals for polar and apolar atoms, and peaks of local atom density variance. These peaks disappear with increasing temperature due to the disruption of segregated domains. In domain-forming liquids, apolar atoms are more homogeneously distributed in space than polar atoms. In addition, the probability of molecular-sized cavity formation is significantly higher in apolar domains, which determines better solubility of apolar species in domain-forming ILs. The suggested approaches can be applied to various nanostructured liquids including both ionic and molecular solvents and mixtures, as well as other systems with mesoscale ordering.
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Affiliation(s)
- Igor A Sedov
- Chemical Institute, Kazan Federal University, Kremlevskaya Str., 18, Kazan, 420008, Russian Federation.
| | - Timur I Magsumov
- Chemical Institute, Kazan Federal University, Kremlevskaya Str., 18, Kazan, 420008, Russian Federation.
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6
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Filippov A, Antzutkin ON, Arkhipov VP, Gnezdilov OI. Diffusivity of ethylammonium nitrate protic ionic liquid confined in porous glasses. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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7
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Stephens NM, Masching HP, Walid MKI, Petrich JW, Anderson JL, Smith EA. Temperature-Dependent Constrained Diffusion of Micro-Confined Alkylimidazolium Chloride Ionic Liquids. J Phys Chem B 2022; 126:4324-4333. [PMID: 35649257 DOI: 10.1021/acs.jpcb.2c01588] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alkylimidazolium chloride ionic liquids (ILs) have many uses in a variety of separation systems, including micro-confined separation systems. To understand the separation mechanism in these systems, the diffusion properties of analytes in ILs under relevant operating conditions, including micro-confinement dimension and temperature, should be known. For example, separation efficiencies for various IL-based microextraction techniques are dependent on the sample volume and temperature. Temperature-dependent (20-100 °C) fluorescence recovery after photobleaching (FRAP) was utilized to determine the diffusion properties of a zwitterionic, hydrophilic dye, ATTO 647, in alkylimidazolium chloride ILs in micro-confined geometries. These micro-confined geometries were generated by sandwiching the IL between glass substrates that were separated by ∼1 to 100 μm. From the measured temperature-dependent FRAP data, we note alkyl chain length-, thickness-, and temperature-dependent diffusion coefficients, with values ranging from 0.021 to 46 μm2/s. Deviations from Brownian diffusion are observed at lower temperatures and increasingly less so at elevated temperatures; the differences are attributed to alterations in intermolecular interactions that reduce temperature-dependent nanoscale structural heterogeneities. The temperature- and thickness-dependent data provide a useful foundation for efficient design of micro-confined IL separation systems.
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Affiliation(s)
- Nicole M Stephens
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3111, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, United States
| | - Hayley P Masching
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3111, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, United States
| | - Mohammad K I Walid
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, United States
| | - Jacob W Petrich
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3111, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, United States
| | - Jared L Anderson
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3111, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, United States
| | - Emily A Smith
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3111, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, United States
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8
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Translational and reorientational dynamics of ionic liquid-based fluorine-free lithium-ion battery electrolytes. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.117001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Filippov A, Gnezdilov OI, Antzutkin ON. Dynamics of ethylammonium nitrate near PTFE surface. Magn Reson Imaging 2021; 85:102-107. [PMID: 34678437 DOI: 10.1016/j.mri.2021.10.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/17/2021] [Accepted: 10/17/2021] [Indexed: 11/26/2022]
Abstract
Self-diffusion of ions in the protic ionic liquid ethylammonium nitrate (EAN) was studied by 1H NMR pulsed field gradient techniques between 294 and 393 K in the presence of a PTFE insert in a 5-mm NMR tube. At all temperatures, the bulk diffusion of ions (measured by 1H and 15N NMR) can be described by a unique diffusion coefficient. The presence of solid hydrophobic surfaces of PTFE induces regions of EAN in their vicinity, where diffusion of ions, both cations and anions, is reduced compared to the bulk values. An additional line-shape analysis in 1H NMR spectra showed that local mobility of ethylammonium cations in the surface layers near PTFE is also reduced.
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Affiliation(s)
- Andrei Filippov
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden; Medical and Biological Physics, Kazan State Medical University, 420012 Kazan, Russia.
| | - Oleg I Gnezdilov
- Institute of Physics, Kazan Federal University, 420008 Kazan, Russia
| | - Oleg N Antzutkin
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden
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10
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Filippov A, Alexandrov AS, Gimatdinov R, Ullah Shah F. Unusual ion transport behaviour of ethylammonium nitrate mixed with lithium nitrate. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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11
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Bridges CA, Martins ML, Jafta CJ, Sun XG, Paranthaman MP, Liu J, Dai S, Mamontov E. Dynamics of Emim + in [Emim][TFSI]/LiTFSI Solutions as Bulk and under Confinement in a Quasi-liquid Solid Electrolyte. J Phys Chem B 2021; 125:5443-5450. [PMID: 34003647 DOI: 10.1021/acs.jpcb.1c02383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Quasi-liquid solid electrolytes are a promising alternative for next-generation Li batteries. These systems combine the safety of solid electrolytes with the desired properties of liquids and are typically formed by solutions of Li salts in ionic liquids incorporated into solid matrices. Here, we present a fundamental understanding of the transport properties in solutions of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]), either in bulk form or incorporated in a boron nitride (BN) matrix. We performed a series of quasi-elastic neutron scattering experiments that, given the high incoherent neutron scattering cross section of hydrogen, allowed us to focus on the Emim+ dynamics. First, [Emim][TFSI]/LiTFSI solutions (0.5 and 2.5 mol·kg-1) were investigated and we show how the increase in the concentration reduces the Emim+ mobility and increases the activation energy of their long-range motions. Then, the 0.5 mol·kg-1 solution was incorporated into the BN matrix and we report that the diffusivities of the Emim+ cations that remain mobile under confinement are highly accelerated in comparison with the bulk sample and the activation energy of these motions is drastically reduced. We present the experimental evidence that this effect is related to the content of the Emim+ cations immobilized near the surfaces of the BN pores.
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Affiliation(s)
- C A Bridges
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - M L Martins
- Neutron Scattering Division, Oak Ridge National Laboratory, P.O. Box 2008 MS6455, Oak Ridge, Tennessee 37831, United States
| | - C J Jafta
- Electrification and Energy Infrastructures, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - X G Sun
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - M P Paranthaman
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - J Liu
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - S Dai
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - E Mamontov
- Neutron Scattering Division, Oak Ridge National Laboratory, P.O. Box 2008 MS6455, Oak Ridge, Tennessee 37831, United States
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12
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Effect of rotating magnetic field on the diffusivity of ethylammonium nitrate ionic liquid confined between micrometer-spaced glass plates. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Overbeck V, Appelhagen A, Rößler R, Niemann T, Ludwig R. Rotational correlation times, diffusion coefficients and quadrupolar peaks of the protic ionic liquid ethylammonium nitrate by means of 1H fast field cycling NMR relaxometry. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114983] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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14
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Kinsey T, Glynn K, Cosby T, Iacob C, Sangoro J. Ion Dynamics of Monomeric Ionic Liquids Polymerized In Situ within Silica Nanopores. ACS APPLIED MATERIALS & INTERFACES 2020; 12:44325-44334. [PMID: 32886472 DOI: 10.1021/acsami.0c12381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Polymerized ionic liquids are a promising class of versatile solid-state electrolytes for applications ranging from electrochemical energy storage to flexible smart materials that remain limited by their relatively low ionic conductivities compared to conventional electrolytes. Here, we show that the in situ polymerization of the vinyl cationic monomer, 1-ethyl-3-vinylimidazolium with the bis(trifluoromethanesulfonyl)imide counteranion, under nanoconfinement within 7.5 ± 1.0 nm diameter nanopores results in a nearly 1000-fold enhancement in the ionic conductivity compared to the material polymerized in bulk. Using insights from broadband dielectric and Raman spectroscopic techniques, we attribute these results to the role of confinement on molecular conformations, ion coordination, and subsequently the ionic conductivity in the polymerized ionic liquid. These results contribute to the understanding of the dynamics of nanoconfined molecules and show that in situ polymerization under nanoscale geometric confinement is a promising path toward enhancing ion conductivity in polymer electrolytes.
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Affiliation(s)
- Thomas Kinsey
- The Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee 37916, United States
| | - Kaitlin Glynn
- The Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee 37916, United States
| | - Tyler Cosby
- Department of Chemistry, US Naval Academy, Annapolis, Maryland 21402, United States
| | - Ciprian Iacob
- National Research and Development Institute for Cryogenic and Isotopic Technologies, ICSI Rm, Valcea, Romania 240050
- Karlsruhe Institute of Technology (KIT), Institute for Chemical Technology and Polymer Chemistry, Karlsruhe, Germany 76128
| | - Joshua Sangoro
- The Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee 37916, United States
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15
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Gnezdilov OI, Antzutkin ON, Gimatdinov R, Filippov A. Temperature dependence of 1H NMR chemical shifts and diffusivity of confined ethylammonium nitrate ionic liquid. Magn Reson Imaging 2020; 74:84-89. [PMID: 32949669 DOI: 10.1016/j.mri.2020.09.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 11/30/2022]
Abstract
Some ionic liquids (ILs) change their dynamic properties when placed in a confinement between polar surfaces (Filippov et al., Phys. Chem. Chem. Phys. 2018, 20, 6316). The diffusivities of ions and NMR relaxation times in these ILs also reversibly change under a strong static magnetic field. The mechanisms of these phenomena are not clear, but it has been suggested that they involve modified hydrogen-bonding networks formed in these ILs in the presence of polar surfaces. To obtain a better understanding of these effects, we performed temperature-dependent measurements of chemical shifts and diffusion coefficients for ethylammonium nitrate (EAN) IL in the bulk phase (IB) and confined in layers with a thickness of ~4 μm between quartz plates unexposed (I phase) and exposed (IMF phase) to a static magnetic field of 9.4 T. It was shown that the NMR chemical shift of NH3 protons of EAN in the I phase is strongly shifted upfield, ~0.0145 ppm/K, which is due to weakening of the hydrogen-bonding network of the confined EAN. Exposure to the magnetic field leads to restitution of the hydrogen-bonding (H-bonding network). The temperature dependences of diffusion coefficients follow the order D(I) > D(IB) > D(IMF) and can be described by a Vogel-Fulcher-Tammann approach with variation of the pre-exponential factor, which is determined by the strength of the H-bonding network. Confinement of EAN between plates (IB → I) is an endothermic process, while processes occurring in a magnetic field, I → IMF and IMF → I, are exothermic and endothermic, respectively.
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Affiliation(s)
| | - Oleg N Antzutkin
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden; Department of Physics, Warwick University, Coventry CV4 7AL, UK
| | | | - Andrei Filippov
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden; Kazan State Medical University, 420012 Kazan, Russia.
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16
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Self-diffusion in ionic liquids with nitrate anion: Effects of confinement between glass plates and static magnetic field. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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17
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Filippov A, Antzutkin ON, Shah FU. Rapid carbene formation increases ion diffusivity in an imidazolium acetate ionic liquid confined between polar glass plates. Phys Chem Chem Phys 2019; 21:22531-22538. [PMID: 31588443 DOI: 10.1039/c9cp04504j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
1-Ethyl-3-methyl-imidazolium acetate ([EMIM][OAc]) is one of the most widely used ionic liquids for various applications. This study is focussed on the chemical stability of [EMIM][OAc] on the surfaces of polar glass plates. 1H and 13C NMR spectroscopy and NMR diffusometry of [EMIM][OAc] IL confined between glass plates with a specific surface area 105-106 m-1 are thoroughly investigated. A rapid and spontaneous reaction took place on the surfaces of glass plates leading to the formation of neutral chemical moieties as evident by the appearance of new signals in the 1H NMR spectra. These new products are assigned as N-heterocyclic carbene (NHC) and acetic acid. These neutral chemical moieties have significantly increased the ion diffusivity by dissociation of the cation and the anion in [EMIM][OAc] IL. The yield and rate of formation of NHC and acetic acid are found to increase with the increasing surface area of polar glass plates and the time of contact between the IL and glass surfaces. Based on NMR spectroscopy, a dissociative reaction mechanism is proposed for the formation of free NHC in the neat [EMIM][OAc] IL.
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Affiliation(s)
- Andrei Filippov
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden. and Kazan State Medical University, 420012 Kazan, Russia
| | - Oleg N Antzutkin
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden. and Department of Physics, Warwick University, Coventry CV4 7AL, UK
| | - Faiz Ullah Shah
- Chemistry of Interfaces, Luleå University of Technology, SE-97187 Luleå, Sweden.
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18
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Merz S, Jakes P, Taranenko S, Eichel RA, Granwehr J. Dynamics of [Pyr 13][Tf 2N] ionic liquid confined to carbon black. Phys Chem Chem Phys 2019; 21:17018-17028. [PMID: 31348470 DOI: 10.1039/c9cp02651g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The intrinsic ionic nature of room temperature ionic liquids (RTILs) bears the potential to replace classical aqueous electrolytes in electrochemical applications, for example in metal-air batteries. For a systematic adjustment of RTIL properties in porous cathodes, the ionic arrangement under confinement is of prime importance. Using spectrally resolved pulsed gradient stimulated echo nuclear magnetic resonance (PGSTE-NMR) and spin-lattice NMR relaxation time (T1) distributions, the dynamics of 1-methyl-1-propylpyrrolidiniumbis(trifluoromethylsulfonyl)imide ([Pyr13][Tf2N]) confined to carbon black were investigated. A considerable dependence of the [PYR13] mobility on the loading fraction of the carbon black pore space was found. There is evidence for a preferential layering of the RTIL adjacent to the carbon surface and a dependence of the ionic configuration on the local structure of the carbon surface. The inversion efficiency of inversion-recovery T1 data indicates a quasi-stationary layer at the carbon surface with solid-like properties, where the bulk-like properties of the RTIL are adopted as the distance to the surface increases. From the NMR diffusion data an intermediate layer between the quasi-stationary and the bulk-like RTIL is evident. This layer shows a particularly strong pore space loading dependence. While it has an anisotropic, two-dimensional mobility with reduced diffusion perpendicular to the surface at any loading, when it interfaces a gas phase at low loading its mobility is higher than bulk diffusion by up to an order of magnitude and chemical exchange with other layers is low. This layer appears to be of particular importance for the ion exchange between RTIL environments with different spacing from the carbon surface and hence crucial for the overall dynamics of RTILs in the investigated porous environment.
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Affiliation(s)
- Steffen Merz
- Forschungszentrum Juelich, Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), 52425 Juelich, Germany.
| | - Peter Jakes
- Forschungszentrum Juelich, Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), 52425 Juelich, Germany.
| | - Svitlana Taranenko
- Forschungszentrum Juelich, Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), 52425 Juelich, Germany.
| | - Rüdiger-A Eichel
- Forschungszentrum Juelich, Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), 52425 Juelich, Germany. and RWTH Aachen University, Institute of Physical Chemistry, 52074 Aachen, Germany
| | - Josef Granwehr
- Forschungszentrum Juelich, Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), 52425 Juelich, Germany. and RWTH Aachen University, Institute of Technical and Macromolecular Chemistry, 52074 Aachen, Germany
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Filippov A, Gnezdilov OI, Luchkin AG, Antzutkin ON. Self-diffusion of ethylammonium nitrate ionic liquid confined between modified polar glasses. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.04.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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21
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Effect of magnetic field on diffusion of ethylammonium nitrate – water mixtures confined between polar glass plates. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.10.080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Mattea C, Gizatullin B, Stapf S. Dynamics of ionic liquids in poly(vinyl alcohol) porous scaffold. Low field NMR study. Magn Reson Imaging 2018; 56:126-130. [PMID: 30287141 DOI: 10.1016/j.mri.2018.09.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/26/2018] [Indexed: 11/25/2022]
Abstract
In this study molecular dynamics of ionic liquids in poly(vinyl alcohol) scaffolds were investigated. The binary poly(vinyl alcohol) - ionic liquid (PVA-IL) compound was prepared from initial solutions of water, ionic liquid (IL) and poly(vinyl alcohol) (PVA) at different concentrations. Subsequently water was evaporated under open conditions, leaving the scaffold/IL system of interest. Low field nuclear magnetic resonance (NMR) relaxation and diffusion measurements, as well as 2D T1-T2 correlated NMR experiments were performed to determine specific local and translational dynamics properties at different time scales. Data suggest that during water evaporation, partial demixing of IL from the polymeric matrix leaves the remaining solvent confined in the porous structure formed by the PVA polymer. The results show that the translational diffusion, as well as the local rotational molecular dynamics is comparable to the bulk liquid state. Moreover, in partial saturation conditions, diffusion shows enhancements relative to the bulk.
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Affiliation(s)
- Carlos Mattea
- Institute of Physics FG Technische Physik II/Polymerphysik, Technische Universität Ilmenau, D-98684 Ilmenau, Germany.
| | - Bulat Gizatullin
- Institute of Physics FG Technische Physik II/Polymerphysik, Technische Universität Ilmenau, D-98684 Ilmenau, Germany
| | - Siegfried Stapf
- Institute of Physics FG Technische Physik II/Polymerphysik, Technische Universität Ilmenau, D-98684 Ilmenau, Germany
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Filippov A, Gnezdilov OI, Antzutkin ON. Static magnetic field alters properties of confined alkylammonium nitrate ionic liquids. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.07.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Filippov A, Antzutkin ON. Magnetic field effects dynamics of ethylammonium nitrate ionic liquid confined between glass plates. Phys Chem Chem Phys 2018; 20:6316-6320. [DOI: 10.1039/c7cp06554j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diffusion and NMR relaxation in ethylammonium nitrate confined between polar glass plates reversibly altered by application of a static magnetic field.
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Affiliation(s)
- Andrei Filippov
- Chemistry of Interfaces, Luleå University of Technology
- SE-97187 Luleå
- Sweden
- Institute of Physics
- Kazan Federal University
| | - Oleg N. Antzutkin
- Chemistry of Interfaces, Luleå University of Technology
- SE-97187 Luleå
- Sweden
- Department of Physics
- Warwick University
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