1
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Morais EM, Idström A, Evenäs L, Martinelli A. Transport Properties of Protic Ionic Liquids Based on Triazolium and Imidazolium: Development of an Air-Free Conductivity Setup. Molecules 2023; 28:5147. [PMID: 37446808 DOI: 10.3390/molecules28135147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/22/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
The dynamical properties of four protic ionic liquids, based on the ethyltriazolium ([C2HTr124]) and the ethylimidazolium ([C2HIm]) cation, were investigated. The associated anions were the triflate ([TfO]) and the bistriflimide ([TFSI]). Ionic conductivity values and self-diffusion coefficients were measured and discussed, extending the discussion to the concept of fragility. Furthermore, in order to allow the measurement of the ionic conductivity of very small volumes (<0.5 mL) of ionic liquid under an inert and dry atmosphere, a new setup was developed. It was found that the cation nature strongly affected the transport properties, the [C2HTr124] cation resulting in slower dynamics than the [C2HIm] one. This was concluded from both conductivity and diffusivity measurements while for both properties, the anion had a lesser effect. By fitting the conductivity data with the Vogel-Fulcher-Tammann (VFT) equation, we could also estimate the fragility of these ionic liquids, which all fell in the range of very fragile glass-forming materials. Finally, the slower dynamics observed in the triazolium-based ionic liquids can be rationalized by the stronger interactions that this cation establishes with both anions, as deduced from the frequency analysis of relevant Raman signatures and density functional theory (DFT) calculations.
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Affiliation(s)
- Eduardo Maurina Morais
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Alexander Idström
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Lars Evenäs
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Anna Martinelli
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
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2
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Moses AA, Arntsen C. Ab initio molecular dynamics study of proton transport in imidazolium-based ionic liquids with added imidazole. Phys Chem Chem Phys 2023; 25:2142-2152. [PMID: 36562495 DOI: 10.1039/d2cp03262g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Development of efficient anhydrous proton-conducting materials would expand the operational temperature ranges of hydrogen fuels cells (HFCs) and eliminate their dependence on maintaining sufficient hydration levels to function efficiently. Protic ionic liquids (PILs), which have high ionic densities and low vapor pressures, have emerged as a potential material for proton conducting layers in HFCs. In this work, we investigate proton transport via the Grotthuss mechanism in 1-ethylimidazolium bis-(trifluoromethanesulfonyl)imide ([C2HIm][TFSI]) protic ionic liquids with added imidazole (Im0) using ab initio molecular dynamics. In particular, we vary the composition of the systems studied from pure [C2HIm][TFSI] to those where the mole fraction of Im0 is 0.67. Given the large difference in pKa between C2HIm+ and HTFSI, TFSI- does not accept acidic protons from C2HIm+; conversely, imidazolium (HIm+) and C2HIm+ have very similar pKa values, and thus Im0 can readily accept protons. We find that the unprotonated nitrogen on Im0 dominates solvation of the labile protons on C2HIm+ and other Im0 species, resulting in formation of robust imidazole wires. Given the amphoteric nature of Im0, i.e. its ability to accept and donate protons, these wires provide conduits along which protons can rapidly traverse via the Grotthuss mechanism, thereby greatly increasing the proton coefficient of self-diffusion. We find that the average length of the wires increases with added Im0, and thus as the mole fraction of Im0 increases so too does the proton diffusion constant. Lastly, we analyze our trajectories to determine the energy and time scales associated with proton transfer.
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Affiliation(s)
- Aurelia A Moses
- Department of Chemical and Biological Sciences, Youngstown State University, Youngstown, OH, 44555, USA.
| | - Christopher Arntsen
- Department of Chemical and Biological Sciences, Youngstown State University, Youngstown, OH, 44555, USA.
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3
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Zhang L, Liu Z, Yang C, García Sakai V, Tyagi M, Hong L. Conduction Mechanism in Graphene Oxide Membranes with Varied Water Content: From Proton Hopping Dominant to Ion Diffusion Dominant. ACS NANO 2022; 16:13771-13782. [PMID: 35993828 DOI: 10.1021/acsnano.2c00686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Proton conductors, particularly hydrated solid membranes, have various applications in sensors, fuel cells, and cellular biological systems. Unraveling the intrinsic proton transfer mechanism is critical for establishing the foundation of proton conduction. Two scenarios on electrical conduction, the Grotthuss and the vehicle mechanisms, have been reported by experiments and simulations. But separating and quantifying the contributions of these two components from experiments is difficult. Here, we present the conductive behavior of a two-dimensional layered proton conductor, graphene oxide membrane (GOM), and find that proton hopping is dominant at low water content, while ion diffusion prevails with increasing water content. This change in the conduction mechanism is attributable to the layers of water molecules in GOM nanosheets. The overall conductivity is greatly improved by forming one layer of water molecules. It reaches the maximum with two layers of water molecules, resulting from creating a complete hydrogen-bond network within GOM. When more than two layers of water molecules enter the GOM nanosheets, inducing the breakage of the ordered lamellar structure, protons spread in both in-plane and out-of-plane directions inside the GOM. Our results validate the existence of two conduction mechanisms and show their distinct contributions to the overall conductivity. Furthermore, these findings provide an optimization strategy for the design of realizing the fast proton transfer in materials with water participation.
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Affiliation(s)
- Lei Zhang
- School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhuo Liu
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai National Center for Applied Mathematics (SJTU Center) and MOE-LSC, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chenxing Yang
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Victoria García Sakai
- Rutherford Appleton Laboratory, ISIS Neutron and Muon Facility, Science and Technology Facilities Council, Didcot OX11 0QX, United Kingdom
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Liang Hong
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai National Center for Applied Mathematics (SJTU Center) and MOE-LSC, Shanghai Jiao Tong University, Shanghai 200240, China
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4
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Maiti S, Mitra S, Johnson CA, Gronborg KC, Garrett-Roe S, Donaldson PM. pH Jumps in a Protic Ionic Liquid Proceed by Vehicular Proton Transport. J Phys Chem Lett 2022; 13:8104-8110. [PMID: 35997534 PMCID: PMC9442784 DOI: 10.1021/acs.jpclett.2c01457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
The dynamics of excess protons in the protic ionic liquid (PIL) ethylammonium formate (EAF) have been investigated from femtoseconds to microseconds using visible pump mid-infrared probe spectroscopy. The pH jump following the visible photoexcitation of a photoacid (8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt, HPTS) results in proton transfer to the formate of the EAF. The proton transfer predominantly (∼70%) occurs over picoseconds through a preformed hydrogen-bonded tight complex between HPTS and EAF. We investigate the longer-range and longer-time-scale proton-transport processes in the PIL by obtaining the ground-state conjugate base (RO-) dynamics from the congested transient-infrared spectra. The spectral kinetics indicate that the protons diffuse only a few solvent shells from the parent photoacid before recombining with RO-. A kinetic isotope effect of nearly unity (kH/kD ≈ 1) suggests vehicular transfer and the transport of excess protons in this PIL. Our findings provide comprehensive insight into the complete photoprotolytic cycle of excess protons in a PIL.
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Affiliation(s)
- Sourav Maiti
- Central
Laser Facility, RCaH, STFC-Rutherford Appleton
Laboratory, Harwell Science
and Innovation Campus, Didcot OX11 0QX, United Kingdom
| | - Sunayana Mitra
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Clinton A. Johnson
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Kai C. Gronborg
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Sean Garrett-Roe
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Paul M. Donaldson
- Central
Laser Facility, RCaH, STFC-Rutherford Appleton
Laboratory, Harwell Science
and Innovation Campus, Didcot OX11 0QX, United Kingdom
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5
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Jain SK, Rawlings D, Antoine S, Segalman RA, Han S. Confinement Promotes Hydrogen Bond Network Formation and Grotthuss Proton Hopping in Ion-Conducting Block Copolymers. Macromolecules 2022. [DOI: 10.1021/acs.macromol.1c01808] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sheetal K. Jain
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Dakota Rawlings
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Ségolène Antoine
- Materials Department, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Rachel A. Segalman
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Materials Department, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Songi Han
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
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6
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The charge transport mechanism in Brønsted-acidic protic ionic liquid/water systems – An NMR and QENS study. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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7
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8
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Kawata K, Kitada A, Tsuchida N, Saimura M, Nagata T, Katahira M, Fukami K, Murase K. Proton conduction in hydronium solvate ionic liquids affected by ligand shape. Phys Chem Chem Phys 2021; 23:449-456. [PMID: 33320154 DOI: 10.1039/d0cp05025c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigated the ligand dependence of the proton conduction of hydronium solvate ionic liquids (ILs), consisting of a hydronium ion (H3O+), polyether ligands, and a bis[(trifluoromethyl)sulfonyl]amide anion (Tf2N-; Tf = CF3SO2). The ligands were changed from previously reported 18-crown-6 (18C6) to other cyclic or acyclic polyethers, namely, dicyclohexano-18-crown-6 (Dh18C6), benzo-18-crown-6 (B18C6) and pentaethylene glycol dimethyl ether (G5). Pulsed-field gradient spin echo nuclear magnetic resonance results revealed that the protons of H3O+ move faster than those of cyclic 18C6-based ligands but as fast as those of acyclic G5 ligands. Based on these results and density functional theory calculations, we propose that the coordination of a cyclic ether ligand to the H3O+ ion is essential for fast proton conduction in hydronium solvate ILs. Our results attract special interest for many electro- and bio-chemical applications such as electrolyte systems for fuel cells and artificial ion channels for biological cells.
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Affiliation(s)
- Kio Kawata
- Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
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9
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Lin J, Korte C. Influence of the acid-base stoichiometry and residual water on the transport mechanism in a highly-Brønsted-acidic proton-conducting ionic liquid. RSC Adv 2020; 10:42596-42604. [PMID: 35516752 PMCID: PMC9057952 DOI: 10.1039/d0ra08969a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/16/2020] [Indexed: 11/21/2022] Open
Abstract
In this study, Brønsted-acidic proton conducting ionic liquids are considered as potential new electrolytes for polymer membrane fuel cells with operating temperatures above 100 °C. N-Methyltaurine and trifluoromethanesulfonic acid (TfOH) were mixed at various stoichiometric ratios in order to investigate the influence of an acid or base excess. The proton conductivity and self-diffusion of the “neat” and with 6 wt% water samples were investigated by following electrochemical and NMR methods. The composition change in the complete species and the relative proton transport mechanism based on the NMR results are discussed in detail. During fuel cell operation, the presence of significant amounts of residual water is unavoidable. In PEFC electrolytes, the predominating proton transfer process depends on the cooperative mechanism, when PILs are fixed on the polymer matrix within the membrane. Due to the comparable acidity of the cation [2-Sema]+ and the hydroxonium cation, with excess N-methyltaurine or H2O in the compositions, fast proton exchange reactions between the protonated [2-Sema]+ cation, N-methyltaurine and H2O can be envisaged. Thus, an increasing ratio of cooperative proton transport could be observed. Therefore, for polymer membrane fuel cells operating at elevated temperatures, the highly acidic PILs with excess bases are promising candidates for future use as electrolytes. There is a transition between prevailing vehicular and cooperative transport mechanism in base-excess Brønsted-acidic proton-conducting ionic liquids depending on stoichiometry.![]()
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Affiliation(s)
- Jingjing Lin
- Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research - Fuel Cells (IEK-14) Wilhelm-Johnen-Straße 52425 Jülich Germany .,RWTH Aachen University 52062 Aachen Germany
| | - Carsten Korte
- Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research - Fuel Cells (IEK-14) Wilhelm-Johnen-Straße 52425 Jülich Germany .,RWTH Aachen University 52062 Aachen Germany
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10
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Abstract
Solid-state polymer electrolytes and high-concentration liquid electrolytes, such as water-in-salt electrolytes and ionic liquids, are emerging materials to replace the flammable organic electrolytes widely used in industrial lithium-ion batteries. Extensive efforts have been made to understand the ion transport mechanisms and optimize the ion transport properties. This perspective reviews the current understanding of the ion transport and polymer dynamics in liquid and polymer electrolytes, comparing the similarities and differences in the two types of electrolytes. Combining recent experimental and theoretical findings, we attempt to connect and explain ion transport mechanisms in different types of small-molecule and polymer electrolytes from a theoretical perspective, linking the macroscopic transport coefficients to the microscopic, molecular properties such as the solvation environment of the ions, salt concentration, solvent/polymer molecular weight, ion pairing, and correlated ion motion. We emphasize universal features in the ion transport and polymer dynamics by highlighting the relevant time and length scales. Several outstanding questions and anticipated developments for electrolyte design are discussed, including the negative transference number, control of ion transport through precision synthesis, and development of predictive multiscale modeling approaches.
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Affiliation(s)
- Chang Yun Son
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Zhen-Gang Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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11
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Liu S, Tyagi M, Akcora P. Polymer-Coupled Local Dynamics Enhances Conductivity of Ionic Liquids. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01434] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Siqi Liu
- Department of Chemical Engineering & Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, 100 Bureau Dr, Gaithersburg, Maryland 20899, United States
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Pinar Akcora
- Department of Chemical Engineering & Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
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12
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S L V Narayana Y, Yoshida T, Bera MK, Mondal S, Higuchi M. Ni(II)-Based Metallosupramolecular Polymer with Carboxylic Acid Groups: A Stable Platform for Smooth Imidazole Loading and the Anhydrous Proton Channel Formation. ACS OMEGA 2020; 5:14796-14804. [PMID: 32596617 PMCID: PMC7315567 DOI: 10.1021/acsomega.0c01735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
The Ni(II)-based metallosupramolecular polymer with carboxylic acid groups (polyNi) was synthesized via a 1:1 complexation of Ni(II) salt with (4,4'-(9,9-dihexyl-9H-fluorene-2,7-diyl)bis(pyridine-2,6-dicarboxylic acid) for the first time. The divalent state of Ni(II) in the polymer was confirmed by the X-ray absorption fine structure analysis. Smooth loading of imidazole molecules into polyNi proceeded with the help of the carboxylic acid groups to form the imidazole-loaded polyNi (polyNi-Im). Thermogravimetric analysis of polyNi-Im revealed that approximately three imidazole molecules were incorporated per repeating unit of polyNi. The Fourier transform infrared spectrum of polyNi-Im showed a new peak at 3219 cm-1, which shows an ∼73 cm-1 enhancement to -N-H of pristine imidazole. The peak suggests the formation of an imidazolium cation in the polymer. Powder X-ray diffraction indicated no degradation of the polymer structure during the imidazole loading because the diffraction pattern of polyNi-Im was almost the same as that of polyNi except for the presence of peaks corresponding to the imidazole molecules. Interestingly, the scanning electron microscopy measurement showed a large morphological change to uniform spherical particles by loading imidazole to the polymer. PolyNi-Im exhibited good proton conductivity (1.05 × 10-2 mS/cm) at a high temperature (120 °C), which is around 7 orders of magnitude higher than that of pristine polyNi because of the proton conduction pathway formation along the polymer chains by the incorporated imidazole molecules.
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Affiliation(s)
- Yemineni S L V Narayana
- Electronic Functional Macromolecules
Group, National Institute for Materials
Science (NIMS), Tsukuba 305-0044, Japan
| | - Takefumi Yoshida
- Electronic Functional Macromolecules
Group, National Institute for Materials
Science (NIMS), Tsukuba 305-0044, Japan
| | - Manas Kumar Bera
- Electronic Functional Macromolecules
Group, National Institute for Materials
Science (NIMS), Tsukuba 305-0044, Japan
| | - Sanjoy Mondal
- Electronic Functional Macromolecules
Group, National Institute for Materials
Science (NIMS), Tsukuba 305-0044, Japan
| | - Masayoshi Higuchi
- Electronic Functional Macromolecules
Group, National Institute for Materials
Science (NIMS), Tsukuba 305-0044, Japan
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13
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Zhu Z, Luo X, Sokolov AP, Paddison SJ. Proton Transfer in Phosphoric Acid-Based Protic Ionic Liquids: Effects of the Base. J Phys Chem A 2020; 124:4141-4149. [PMID: 32314922 DOI: 10.1021/acs.jpca.0c02863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electronic structure calculations were performed to understand highly decoupled conductivities recently reported in protic ionic liquids (PILs). To develop a molecular-level understanding of the mechanisms of proton conductivity in PILs, minimum-energy structures of trimethylamine, imidazole, lidocaine, and creatinine (CRT) with the addition of one to three phosphoric acid (PA) molecules were determined at the B3LYP/6-311G** level of theory with the inclusion of an implicit solvation model (SMD with ε = 61). The proton affinity of the bases and zero-point energy corrected binding energies were computed at a similar level of theory. Proton dissociation from PA occurs in all systems, resulting in the formation of ion pairs due to the relatively strong basicity of the bases (proton acceptors) and the effect of the high dielectric constant solvent in stabilizing the charge separation. The second and third PA molecules preferentially form "ring-like" hydrogen bonds with one another instead of forming hydrogen bonds at the donor and acceptor sites of the bases. Potential energy scans reveal that the bases with stronger proton affinity exert greater influence on the energetics of proton transfer between the individual PA molecules. However, the effects are minimal when shifted into a single-well from a double-well potential. Barrierless proton transfer was observed to occur in the CRT system with several PA molecules present, implying that the CRT may be a promising PA-based PIL.
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Affiliation(s)
- Zhenghao Zhu
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Xubo Luo
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Alexei P Sokolov
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Stephen J Paddison
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
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14
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Li A, Yan T. Proton Propensity and Orientation of Imidazolium Cation at Liquid Imidazole-Vacuum Interface: A Molecular Dynamics Simulation. J Phys Chem B 2020; 124:4010-4016. [PMID: 32309950 DOI: 10.1021/acs.jpcb.9b11918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Imidazole has gained attention as an alternative to anhydrous proton conductor in high-temperature proton exchange membrane fuel cells. A detailed investigation of proton propensity and the orientation of the imidazolium cation at the liquid-vacuum interface is important for understanding the interfacial properties of imidazole-based proton-conductive materials. Here, we perform all-atom molecular dynamics simulation on a slab model of the liquid imidazole-vacuum interface. Proton transportation process between the imidazolium cation and neutral imidazole molecules is described by the multistate empirical valence bond model of imidazole developed previously. The imidazolium cation shows a tendency to stay in the bulk region rather than at the outermost surface, and the NN vectors and norm vectors of both the imidazolium cation and imidazole molecules are more probable to be perpendicular to the surface normal vector at the interface than in the bulk. The orientation of the hydrogen bond cluster shows the same tendency as the NN vectors, which indicates that proton transportation along the direction of the surface normal vector is hindered. The instantaneous surface analyses show that the fluctuation is depressed when the imidazolium cation is near the outermost surface, which makes it less favorable for the cation appearing at the interface.
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Affiliation(s)
- Ailin Li
- Institute of New Energy Chemistry, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin 300350, China.,College of Science, Civil Aviation University of China, Tianjin 300300, China
| | - Tianying Yan
- Institute of New Energy Chemistry, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin 300350, China
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15
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Hasani M, Varela LM, Martinelli A. Short-Range Order and Transport Properties in Mixtures of the Protic Ionic Liquid [C 2HIm][TFSI] with Water or Imidazole. J Phys Chem B 2020; 124:1767-1777. [PMID: 31999926 DOI: 10.1021/acs.jpcb.9b10454] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We investigate the effect of adding different molecular cosolvents, water or imidazole, to the protic ionic liquid 1-ethylimidazolium bis(trifluoromethanesulfonyl)imide, i.e., [C2HIm][TFSI]. We explore how the added cosolvent distributes within the ionic liquid by means of molecular dynamics simulations and X-ray scattering. We also analyze the degree of short-range heterogeneity in the resulting mixtures, finding that while imidazole easily mixes with the protic ionic liquid, water tends to form small clusters in its own water-rich domains. These differences are rationalized by invoking the nature of intermolecular interactions. In aqueous mixtures water-water hydrogen bonds are more likely to form than water-ion hydrogen bonds (water-TFSI bonds being particularly weak), while imidazole can interact with both cations and anions. Hence, the cation-anion association is negligibly influenced by the presence of water, whereas the addition of imidazole creates solvent-separated ion pairs and is thus able to also increase the ionicity. As a consequence of these structural and interactional features, transport properties like self-diffusion and ionic conductivity also show different composition dependencies. While the mobility of both ions and solvent is increased considerably by the addition of water, upon adding imidazole this property changes significantly only for molar fractions of imidazole above 0.6. At these molar fractions, which correspond to a base-excess composition, the imidazole/[C2HIm][TFSI] mixture behaves as a glass-forming liquid with suppressed phase transitions, while homomixtures such as imidazole/[HIm][TFSI] can display a eutectic point.
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Affiliation(s)
- Mohammad Hasani
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Luis Miguel Varela
- Department of Applied and Particle Physics, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Anna Martinelli
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden
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16
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Adenusi H, Le Donne A, Porcelli F, Bodo E. Ab Initio Molecular Dynamics Study of Phospho-Amino Acid-Based Ionic Liquids: Formation of Zwitterionic Anions in the Presence of Acidic Side Chains. J Phys Chem B 2020; 124:1955-1964. [PMID: 32037824 PMCID: PMC7997564 DOI: 10.1021/acs.jpcb.9b09703] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
We
present a computational analysis of the complex proton-transfer
processes in two protic ionic liquids based on phosphorylated amino
acid anions. The structure and the short time dynamics have been analyzed
via ab initio and semi-empirical molecular dynamics. Given the presence
of mobile protons on the side chain, such ionic liquids may represent
a viable prototype of highly conductive ionic mediums. The results
of our simulations are not entirely satisfactory in this respect.
Our results indicate that conduction in these liquids may be limited
due to a quick quenching of the proton-transfer processes. In particular,
we have found that, while proton migration does occur on very short
timescales, the amino groups act as proton scavengers preventing an
efficient proton migration. Despite their limits as conductive mediums,
we show that these ionic liquids possess an unconventional microscopic
structure, where the anionic component is made by amino acid anions
that the aforementioned proton transfer has transformed into zwitterionic
isomers. This unusual chemical structure is relevant because of the
recent use of amino acid-based ionic liquids, such as CO2 absorbent.
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Affiliation(s)
- Henry Adenusi
- Chemistry Department, University of Rome "La Sapienza", Piazzale Aldo Moro 5, 00185 Rome Italy
| | - Andrea Le Donne
- Chemistry Department, University of Rome "La Sapienza", Piazzale Aldo Moro 5, 00185 Rome Italy
| | - Francesco Porcelli
- Chemistry Department, University of Rome "La Sapienza", Piazzale Aldo Moro 5, 00185 Rome Italy
| | - Enrico Bodo
- Chemistry Department, University of Rome "La Sapienza", Piazzale Aldo Moro 5, 00185 Rome Italy
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17
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Liu S, Liedel C, Tarakina NV, Osti NC, Akcora P. Dynamics of ionic liquids in the presence of polymer-grafted nanoparticles. NANOSCALE 2019; 11:19832-19841. [PMID: 31368472 DOI: 10.1039/c9nr04204k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We incorporated polymer-grafted nanoparticles into ionic and zwitterionic liquids to explore the solvation and confinement effects on their heterogeneous dynamics using quasi-elastic neutron scattering (QENS). 1-Hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HMIM-TFSI) mixed with deuterated poly(methyl methacrylate) (d-PMMA)-grafted nanoparticles is studied to unravel how dynamic coupling between PMMA and HMIM-TFSI influence the fast and slow diffusion characteristics of the HMIM+ cations. The zwitterionic liquid, 1-butyl-3-methyl imidazole-2-ylidene borane (BMIM-BH3) is critically selected and mixed with PMMA-grafted nanoparticles for comparison in this work as its ions do not self-dissociate and it does not couple with PMMA through ion-dipole interactions as HMIM-TFSI does. We find that long-range unrestricted diffusion of HMIM+ cations is higher in well-dispersed particles than in aggregated particle systems, whereas the localized diffusion of HMIM+ is measured to be higher in close-packed particles. Translational diffusion dynamics of BMIM-BH3 is not influenced by any particle structures suggesting that zwitterions do not interact with PMMA. This difference between two ionic liquid types enables us to decouple polymer effects from the diffusion of ionic liquids, which is integral to understand the ionic transport mechanism in ionic liquids confined in polymer-grafted nanoparticle electrolytes.
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Affiliation(s)
- Siqi Liu
- Department of Chemical Engineering & Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030, USA.
| | - Clemens Liedel
- Department of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, Potsdam 14476, Germany
| | - Nadezda V Tarakina
- Department of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, Potsdam 14476, Germany
| | - Naresh C Osti
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Pinar Akcora
- Department of Chemical Engineering & Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030, USA.
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18
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Hasani M, Nordstierna L, Martinelli A. Molecular dynamics involving proton exchange of a protic ionic liquid-water mixture studied by NMR spectroscopy. Phys Chem Chem Phys 2019; 21:22014-22021. [PMID: 31556889 DOI: 10.1039/c9cp03563j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protic ionic liquids (PILs) are proposed as alternative anhydrous proton conducting electrolytes for intermediate temperature fuel cells. One of the key factors in their performance as electrolytes, as far as charge transport is concerned, is their proton conductivity. Noting the success of water-containing electrolytes and recognising faster proton mobility than structural relaxation (via mechanisms such as Grotthuss) as their advantage, such an advantage is envisaged for PILs and in some cases deduced. As extended hydrogen bond networks and proton exchange are at the heart of these mechanisms, here we report our results on a prototypical characterisation of proton exchange in a PIL (C2HimNTf2)-water mixture. NMR lineshape analysis and exchange spectroscopy (EXSY) are used to quantify the proton exchange rate. The obtained exchange rate is then used to explain the diffusion behaviour of the exchangeable proton as measured by pulse field gradient NMR methods; a marginal anomaly in the translational dynamics of the exchangeable proton in the form of a faster NH proton is observed. As far as we know this is the first report on systematic characterisation of proton exchange in PILs with the aim of understanding its effect on translational motion as a way of discerning exchange related mobility anomalies.
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Affiliation(s)
- Mohammad Hasani
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
| | - Lars Nordstierna
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
| | - Anna Martinelli
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
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19
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Watanabe H, Umecky T, Arai N, Nazet A, Takamuku T, Harris KR, Kameda Y, Buchner R, Umebayashi Y. Possible Proton Conduction Mechanism in Pseudo-Protic Ionic Liquids: A Concept of Specific Proton Conduction. J Phys Chem B 2019; 123:6244-6252. [DOI: 10.1021/acs.jpcb.9b03185] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Hikari Watanabe
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi, 2-no-cho, Nishi-ku, Niigata City 950-2181, Japan
| | - Tatsuya Umecky
- Graduate School of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
| | - Nana Arai
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi, 2-no-cho, Nishi-ku, Niigata City 950-2181, Japan
| | - Andreas Nazet
- Institute of Theoretical and Physical Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
| | - Toshiyuki Takamuku
- Graduate School of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
| | - Kenneth R. Harris
- School of Science, The University of New South Wales, P.O. Box 7916, Canberra BC, Australian Capital Territory 2610, Australia
| | - Yasuo Kameda
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, 1-4-12, Kojirakawa-machi, Yamagata City, Yamagata 990-8560, Japan
| | - Richard Buchner
- Institute of Theoretical and Physical Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
| | - Yasuhiro Umebayashi
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi, 2-no-cho, Nishi-ku, Niigata City 950-2181, Japan
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20
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Abdurrokhman I, Elamin K, Danyliv O, Hasani M, Swenson J, Martinelli A. Protic Ionic Liquids Based on the Alkyl-Imidazolium Cation: Effect of the Alkyl Chain Length on Structure and Dynamics. J Phys Chem B 2019; 123:4044-4054. [PMID: 30995045 DOI: 10.1021/acs.jpcb.9b01274] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Protic ionic liquids are known to form extended hydrogen-bonded networks that can lead to properties different from those encountered in the aprotic analogous liquids, in particular with respect to the structure and transport behavior. In this context, the present paper focuses on a wide series of 1-alkyl-imidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, [HC nIm][TFSI], with the alkyl chain length ( n) on the imidazolium cation varying from ethyl ( n = 2) to dodecyl ( n = 12). A combination of several methods, such as vibrational spectroscopy, wide-angle X-ray scattering (WAXS), broadband dielectric spectroscopy, and 1H NMR spectroscopy, is used to understand the correlation between local cation-anion coordination, nature of nanosegregation, and transport properties. The results indicate the propensity of the -NH site on the cation to form stronger H-bonds with the anion as the alkyl chain length increases. In addition, the position and width of the scattering peak q1 (or the pre-peak), resolved by WAXS and due to the nanosegregation of the polar from the nonpolar domains, are clearly dependent on the alkyl chain length. However, we find no evidence from pulsed-field gradient NMR of a proton motion decoupled from molecular diffusion, hypothesized to be facilitated by the longer N-H bonds localized in the segregated ionic domains. Finally, for all protic ionic liquids investigated, the ionic conductivity displays a Vogel-Fulcher-Tammann dependence on inverse temperature, with an activation energy Ea that also depends on the alkyl chain length, although not strictly linearly.
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21
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Linking Structure to Dynamics in Protic Ionic Liquids: A Neutron Scattering Study of Correlated and Single-Particle Motions. Sci Rep 2018; 8:16400. [PMID: 30401950 PMCID: PMC6219547 DOI: 10.1038/s41598-018-34481-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/18/2018] [Indexed: 11/22/2022] Open
Abstract
Coupling between dynamical heterogeneity of ionic liquids and their structural periodicity on different length-scales can be directly probed by quasielastic neutron scattering with polarization analysis. The technique provides the tools to investigate single-particle and cooperative ion motions separately and, thus, dynamics of ion associations affecting the net charge transport can be experimentally explored. The focus of this study is the structure-dynamic relationship in the protic ionic liquid, triethylammonium triflate, characterized by strong hydrogen bonds between cations and anions. The site-selective deuterium/hydrogen-isotope substitution was applied to modulate the relative contributions of different atom groups to the total coherent and incoherent scattering signal. This approach in combination with molecular dynamics simulations allowed us to obtain a sophisticated description of cation self-diffusion and confined ion pair dynamics from the incoherent spectral component by using the acidic proton as a tagged particle. The coherent contribution of the neutron spectra demonstrated substantial ion association leading to collective ion migration that preserves charge alteration on picosecond time scale, as well as correlation of the localized dynamics occurring between adjacent ions.
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22
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Yaghini N, Abdurrokhman I, Hasani M, Martinelli A. Transport properties and intermolecular interactions in binary mixtures based on the protic ionic liquid ethylimidazolium triflate and ethylene glycol. Phys Chem Chem Phys 2018; 20:22980-22986. [PMID: 30156221 DOI: 10.1039/c8cp03093f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The binary mixture based on the protic ionic liquid (PIL) ethylimidazolium triflate (C2HImTfO) and the diol compound ethylene glycol (EG) has been investigated in the whole composition range from pure PIL to pure EG. At 30 °C the addition of EG increases both the ionic conductivity and the self-diffusivity of the ions. These quantities, however, change at different rates suggesting that the ionicity of the system is composition dependent. This behaviour is explained by means of new intermolecular forces established when a second compound like EG is introduced into the ionic network. More specifically, a complex H-bonded network is formed that involves the -NH group of the cation, the -OH group of EG and the -SO3 group of the anion. This configuration may increase the fluidity of the mixture but not necessarily the ionic dissociation. Moreover, diffusion NMR results indicate the occurrence of local proton dynamics, which arise from a proton exchange between the -NH of the cation and the -OH of EG, providing the requisite for a long-range Grotthuss mechanism of proton transport.
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Affiliation(s)
- Negin Yaghini
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
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23
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Garaga MN, Dracopoulos V, Werner-Zwanziger U, Zwanziger JW, Maréchal M, Persson M, Nordstierna L, Martinelli A. A long-chain protic ionic liquid inside silica nanopores: enhanced proton mobility due to efficient self-assembly and decoupled proton transport. NANOSCALE 2018; 10:12337-12348. [PMID: 29780989 DOI: 10.1039/c8nr02031k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report enhanced protonic and ionic dynamics in an imidazole/protic ionic liquid mixture confined within the nanopores of silica particles. The ionic liquid is 1-octylimidazolium bis(trifluoromethanesulfonyl)imide ([HC8Im][TFSI]), while the silica particles are microsized and characterized by internal well connected nanopores. We demonstrate that the addition of imidazole is crucial to promote a proton motion decoupled from molecular diffusion, which occurs due to the establishment of new N-HN hydrogen bonds and fast proton exchange events in the ionic domains, as evidenced by both infrared and 1H NMR spectroscopy. An additional reason for the decoupled motion of protons is the nanosegregated structure adopted by the liquid imidazole/[HC8Im][TFSI] mixture, with segregated polar and non-polar nano-domains, as clearly shown by WAXS data. This arrangement, promoted by the length of the octyl group and thus by significant chain-chain interactions, reduces the mobility of molecules (Dmol) more than that of protons (DH), which is manifested by DH/Dmol ratios greater than three. Once included into the nanopores of hydrophobic silica microparticles, the nanostructure of the liquid mixture is preserved with slightly larger ionic domains, but effects on the non-polar ones are unclear. This results in a further enhancement of proton motion with localised paths of conduction. These findings demonstrate significant progress in the design of proton conducting materials via tailor-made molecular structures as well as by smart exploitation of confinement effects. Compared to other imidazole-based proton conducting materials that are crystalline up to 90 °C or above, the gel materials that we propose are useful for applications at room temperature, and can thus find applications in e.g. intermediate temperature proton exchange fuel cells.
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24
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Silletta EV, Xu Z, Youssef M, Sacanna S, Jerschow A. Monitoring Molecular Transport across Colloidal Membranes. J Phys Chem B 2018; 122:4931-4936. [PMID: 29665683 DOI: 10.1021/acs.jpcb.8b01638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The controlled shaping and surface functionalization of colloidal particles has provided opportunities for the development of new materials and responsive particles. The possibility of creating hollow particles with semipermeable walls allows modulating molecular transport properties on colloidal length scales. While shapes and sizes can typically be observed by optical means, the underlying chemical and physical properties are often invisible. Here, we present measurements of cross-membrane transport via pulsed field gradient NMR in packings of hollow colloidal particles. The work is conducted using a systematic selection of particle sizes, wall permeabilities, and osmotic pressures and allows tracking organic molecules as well as ions. It is also shown that, while direct transport of molecules can be measured, indirect markers can be obtained for invisible species via the osmotic pressure as well. The cross-membrane transport information is important for applications in nanoconfinement, nanofiltration, nanodelivery, or nanoreactor devices.
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Affiliation(s)
- Emilia V Silletta
- Department of Chemistry , New York University , 100 Washington Square East , New York , New York 10003 , United States
| | - Zhe Xu
- Department of Chemistry , New York University , 100 Washington Square East , New York , New York 10003 , United States
| | - Mena Youssef
- Department of Chemistry , New York University , 100 Washington Square East , New York , New York 10003 , United States
| | - Stefano Sacanna
- Department of Chemistry , New York University , 100 Washington Square East , New York , New York 10003 , United States
| | - Alexej Jerschow
- Department of Chemistry , New York University , 100 Washington Square East , New York , New York 10003 , United States
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25
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Sanoja GE, Schauser NS, Bartels JM, Evans CM, Helgeson ME, Seshadri R, Segalman RA. Ion Transport in Dynamic Polymer Networks Based on Metal–Ligand Coordination: Effect of Cross-Linker Concentration. Macromolecules 2018. [DOI: 10.1021/acs.macromol.7b02141] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Gabriel E. Sanoja
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
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26
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Yaghini N, Gómez-González V, Varela LM, Martinelli A. Structural origin of proton mobility in a protic ionic liquid/imidazole mixture: insights from computational and experimental results. Phys Chem Chem Phys 2018; 18:23195-206. [PMID: 27499376 DOI: 10.1039/c6cp03058k] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure, dynamics, and phase behavior of a binary mixture based on the protic ionic liquid 1-ethylimidazolium bis(trifluoromethanesulfonyl)imide (C2HImTFSI) and imidazole are investigated by (1)H NMR spectroscopy, vibrational spectroscopy, diffusion NMR, calorimetric measurements, and molecular dynamics simulations. Particular attention is given to the nature of the H-bonds established and the consequent occurrence of the Grotthuss mechanism of proton transfer. We find that due to their structural similarity, the imidazolium cation and the imidazole molecule behave as interchangeable and competing sites of interaction for the TFSI anion. All investigated properties, that is the phase behavior, strength of ion-ion and ion-imidazole interactions, number of specific H-bonds, density, and self-diffusivity, are composition dependent and show trend changes at mole fractions of imidazole (χ) approximately equal to 0.2 and 0.5. Beyond χ = 0.8 imidazole is not miscible in C2HImTFSI at room temperature. We find that at the equimolar composition (χ ≈ 0.5) a structural transition occurs from an ionic network mainly stabilized by coulombic forces to a mixed phase held together by site specific H-bonds. The same composition also marks a steeper decrease in density and increase in diffusivity, resulting from the preference of imidazole molecules to H-bond to each other in a chain-like manner. As a result of these structural features the Grotthuss mechanism of proton transfer is less favored at the equimolar composition where H-bonds are too stable. By contrast, the Grotthuss mechanism is more pronounced in the low concentration range where imidazole acts as a base pulling the proton of the imidazolium cation. At high imidazole concentrations the contribution from the vehicular mechanism dominates.
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Affiliation(s)
- Negin Yaghini
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
| | - Víctor Gómez-González
- Grupo de Nanomateriales, Fotonica y Materia Blanda, Departamento de Física de la Materia Condensada, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain
| | - Luis M Varela
- Grupo de Nanomateriales, Fotonica y Materia Blanda, Departamento de Física de la Materia Condensada, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain
| | - Anna Martinelli
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
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27
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Turner AH, Imberti S, Swadźba-Kwaśny M, Holbrey JD. Applying neutron diffraction with isotopic substitution to the structure and proton-transport pathways in protic imidazolium bis{(trifluoromethyl)sulfonyl}imide ionic liquids. Faraday Discuss 2018; 206:247-263. [DOI: 10.1039/c7fd00143f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Neutron diffraction with isotopic substitution has been applied to examine the potential for complex-ion formation in protic imidazolium bis{(trifluoromethyl)sulfonyl}imide ionic liquids.
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Affiliation(s)
- Adam H. Turner
- School of Chemistry and Chemical Engineering
- The Queen’s University of Belfast
- Belfast
- UK
| | - Silvia Imberti
- ISIS
- Rutherford Appleton Laboratory
- Harwell Science & Innovation Campus
- Didcot
- UK
| | | | - John D. Holbrey
- School of Chemistry and Chemical Engineering
- The Queen’s University of Belfast
- Belfast
- UK
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28
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Frenzel F, Guterman R, Anton AM, Yuan J, Kremer F. Molecular Dynamics and Charge Transport in Highly Conductive Polymeric Ionic Liquids. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00554] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Falk Frenzel
- Institute
of Experimental Physics I, Leipzig University, Linnéstrasse 5, 04103 Leipzig, Germany
| | - Ryan Guterman
- Department
of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 OT Golm, 14424 Potsdam, Germany
| | - A. Markus Anton
- Institute
of Experimental Physics I, Leipzig University, Linnéstrasse 5, 04103 Leipzig, Germany
| | - Jiayin Yuan
- Department
of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1 OT Golm, 14424 Potsdam, Germany
| | - Friedrich Kremer
- Institute
of Experimental Physics I, Leipzig University, Linnéstrasse 5, 04103 Leipzig, Germany
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29
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Chakraborty C, Rana U, Pandey RK, Moriyama S, Higuchi M. One-Dimensional Anhydrous Proton Conducting Channel Formation at High Temperature in a Pt(II)-Based Metallo-Supramolecular Polymer and Imidazole System. ACS APPLIED MATERIALS & INTERFACES 2017; 9:13406-13414. [PMID: 28368106 DOI: 10.1021/acsami.6b12963] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
One dimensional (1D) Pt(II)-based metallo-supramolecular polymer with carboxylic acids (polyPtC) was synthesized using a new asymmetrical ditopic ligand with a pyridine moiety bearing two carboxylic acids. The carboxylic acids in the polymer successfully served as apohosts for imidazole loaded in the polymer interlayer scaffold to generate highly ordered 1D imidazole channels through the metallo-supramolecular polymer chains. The 1D structure of imidazole loaded polymer (polyPtC-Im) was analyzed in detail by thermogravimetric analysis, powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible and photoluminescence spectroscopic measurements. PolyPtC-Im exhibited proton conductivity of 1.5 × 10-5 S cm-1 at 120 °C under completely anhydrous conditions, which is 6 orders of magnitude higher than that of the pristine metallo-supramolecular polymer.
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Affiliation(s)
- Chanchal Chakraborty
- Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan
- International Center for Materials Nanoarchitectonics (MANA), NIMS , Tsukuba 305-0044, Japan
| | - Utpal Rana
- Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan
| | - Rakesh K Pandey
- Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan
| | - Satoshi Moriyama
- International Center for Materials Nanoarchitectonics (MANA), NIMS , Tsukuba 305-0044, Japan
| | - Masayoshi Higuchi
- Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan
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30
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Ionic Liquid-Based Non-Aqueous Electrolytes for Nickel/Metal Hydride Batteries. BATTERIES-BASEL 2017. [DOI: 10.3390/batteries3010004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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31
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32
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Chopade SA, So S, Hillmyer MA, Lodge TP. Anhydrous Proton Conducting Polymer Electrolyte Membranes via Polymerization-Induced Microphase Separation. ACS APPLIED MATERIALS & INTERFACES 2016; 8:6200-6210. [PMID: 26927732 DOI: 10.1021/acsami.5b12366] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Solid-state polymer electrolyte membranes (PEMs) exhibiting high ionic conductivity coupled with mechanical robustness and high thermal stability are vital for the design of next-generation lithium-ion batteries and high-temperature fuel cells. We present the in situ preparation of nanostructured PEMs incorporating a protic ionic liquid (IL) into one of the domains of a microphase-separated block copolymer created via polymerization-induced microphase separation. This facile, one-pot synthetic strategy transforms a homogeneous liquid precursor consisting of a poly(ethylene oxide) (PEO) macro-chain-transfer agent, styrene and divinylbenzene monomers, and protic IL into a robust and transparent monolith. The resulting PEMs exhibit a bicontinuous morphology comprising PEO/protic IL conducting pathways and highly cross-linked polystyrene (PS) domains. The cross-linked PS mechanical scaffold imparts thermal and mechanical stability to the PEMs, with an elastic modulus approaching 10 MPa at 180 °C, without sacrificing the ionic conductivity of the system. Crucially, the long-range continuity of the PEO/protic IL conducting nanochannels results in an outstanding ionic conductivity of 14 mS/cm at 180 °C. We posit that proton conduction in the protic IL occurs via the vehicular mechanism and the PEMs exhibit an average proton transference number of 0.7. This approach is very promising for the development of high-temperature, robust PEMs with excellent proton conductivities.
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Affiliation(s)
- Sujay A Chopade
- Department of Chemical Engineering and Materials Science and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
| | - Soonyong So
- Department of Chemical Engineering and Materials Science and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
| | - Marc A Hillmyer
- Department of Chemical Engineering and Materials Science and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
| | - Timothy P Lodge
- Department of Chemical Engineering and Materials Science and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
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33
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Sanoja GE, Popere BC, Beckingham BS, Evans CM, Lynd NA, Segalman RA. Structure–Conductivity Relationships of Block Copolymer Membranes Based on Hydrated Protic Polymerized Ionic Liquids: Effect of Domain Spacing. Macromolecules 2016. [DOI: 10.1021/acs.macromol.5b02614] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Gabriel E. Sanoja
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- Joint
Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | | | - Bryan S. Beckingham
- Joint
Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | | | - Nathaniel A. Lynd
- Joint
Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- McKetta
Department of Chemical Engineering, University of Texas, Austin, Texas 78712, United States
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34
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Wojnarowska Z, Knapik J, Rams-Baron M, Jedrzejowska A, Paczkowska M, Krause A, Cielecka-Piontek J, Jaworska M, Lodowski P, Paluch M. Amorphous Protic Ionic Systems as Promising Active Pharmaceutical Ingredients: The Case of the Sumatriptan Succinate Drug. Mol Pharm 2016; 13:1111-22. [PMID: 26836258 DOI: 10.1021/acs.molpharmaceut.5b00911] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this article, we highlight the benefits coming from the application of amorphous protic ionic systems as active pharmaceutical ingredients (APIs). Using the case of the sumatriptan (STR) drug, we show that the conversion of nonionic API to partially ionized amorphous protic succinate salt (STR SUCC) brings a substantial improvement in apparent solubility. Since in general the disordered systems reveal a tendency to self-arrangement during storage, the dominant part of this article is dedicated to the physical stability issue of sumatriptan and its ionic counterpart. To recognize the crystallization tendency of the studied systems, the calorimetric measurements were performed. Additionally, the role of ion dynamics in spontaneous nucleation of amorphous sumatriptan succinate is discussed. The differential scanning calorimetry analysis of ionic and nonionic sumatriptan reveals many similarities in thermal properties of these APIs as well as distinct differences in their resistance against crystallization in the supercooled liquid state. To determine the long-term physical stability of STR SUCC at room temperature conditions, the time scale of structural relaxation below their glass transition temperatures is estimated. We show that in contrast to nonionic materials, τα predictions of STR SUCC are much more complex and require aging experiments.
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Affiliation(s)
- Z Wojnarowska
- Institute of Physics, University of Silesia , Uniwersytecka 4, 40-007 Katowice, Poland.,SMCEBI , 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
| | - J Knapik
- Institute of Physics, University of Silesia , Uniwersytecka 4, 40-007 Katowice, Poland.,SMCEBI , 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
| | - M Rams-Baron
- Institute of Physics, University of Silesia , Uniwersytecka 4, 40-007 Katowice, Poland.,SMCEBI , 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
| | - A Jedrzejowska
- Institute of Physics, University of Silesia , Uniwersytecka 4, 40-007 Katowice, Poland.,SMCEBI , 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
| | - M Paczkowska
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences , Grunwaldzka 6, 60-780 Poznań, Poland
| | - A Krause
- PozLab sp. z.o.o. Parkowa 2, 60-775 Poznań, Poland
| | - J Cielecka-Piontek
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences , Grunwaldzka 6, 60-780 Poznań, Poland
| | - M Jaworska
- Institute of Chemistry, Department of Theoretical Chemistry, University of Silesia , Szkolna 9, 40-006 Katowice, Poland
| | - P Lodowski
- Institute of Chemistry, Department of Theoretical Chemistry, University of Silesia , Szkolna 9, 40-006 Katowice, Poland
| | - M Paluch
- Institute of Physics, University of Silesia , Uniwersytecka 4, 40-007 Katowice, Poland.,SMCEBI , 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
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35
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Evans CM, Sanoja GE, Popere BC, Segalman RA. Anhydrous Proton Transport in Polymerized Ionic Liquid Block Copolymers: Roles of Block Length, Ionic Content, and Confinement. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b02202] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Gabriel E. Sanoja
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94705, United States
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36
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Burankova T, Hempelmann R, Fossog V, Ollivier J, Seydel T, Embs JP. Proton Diffusivity in the Protic Ionic Liquid Triethylammonium Triflate Probed by Quasielastic Neutron Scattering. J Phys Chem B 2015. [DOI: 10.1021/acs.jpcb.5b04000] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tatsiana Burankova
- Department
of Physical Chemistry, Saarland University, Saarbrücken, 66123, Germany
- Laboratory
for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen
PSI, Villigen 5232, Switzerland
| | - Rolf Hempelmann
- Department
of Physical Chemistry, Saarland University, Saarbrücken, 66123, Germany
| | - Verlaine Fossog
- Department
of Physical Chemistry, Saarland University, Saarbrücken, 66123, Germany
| | | | - Tilo Seydel
- Institut Laue-Langevin, Grenoble, 38000, France
| | - Jan P. Embs
- Laboratory
for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen
PSI, Villigen 5232, Switzerland
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37
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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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38
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Wojnarowska Z, Paluch M. Recent progress on dielectric properties of protic ionic liquids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:073202. [PMID: 25634823 DOI: 10.1088/0953-8984/27/7/073202] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Protic ionic liquids (PILs) are key materials for a wide range of emerging technologies. In particular, these systems have long been envisioned as promising candidates for fuel cells. Therefore, in recent years special attention has been devoted to thorough studies of these compounds. Amongst others, dielectric properties of PILs at ambient and elevated pressure have become the subject of intense research. The reason for this lies in the role of broadband dielectric spectroscopy in recognizing the conductivity mechanism in protic ionic systems. In this paper, we summarize the dielectric results of various PILs reflecting recent advances in this field.
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Affiliation(s)
- Zaneta Wojnarowska
- Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
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39
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Wojnarowska Z, Paluch KJ, Shoifet E, Schick C, Tajber L, Knapik J, Wlodarczyk P, Grzybowska K, Hensel-Bielowka S, Verevkin SP, Paluch M. Molecular origin of enhanced proton conductivity in anhydrous ionic systems. J Am Chem Soc 2015; 137:1157-64. [PMID: 25558882 DOI: 10.1021/ja5103458] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Ionic systems with enhanced proton conductivity are widely viewed as promising electrolytes in fuel cells and batteries. Nevertheless, a major challenge toward their commercial applications is determination of the factors controlling the fast proton hopping in anhydrous conditions. To address this issue, we have studied novel proton-conducting materials formed via a chemical reaction of lidocaine base with a series of acids characterized by a various number of proton-active sites. From ambient and high pressure experimental data, we have found that there are fundamental differences in the conducting properties of the examined salts. On the other hand, DFT calculations revealed that the internal proton hopping within the cation structure strongly affects the pathways of mobility of the charge carrier. These findings offer a fresh look on the Grotthuss-type mechanism in protic ionic glasses as well as provide new ideas for the design of anhydrous materials with exceptionally high proton conductivity.
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Affiliation(s)
- Zaneta Wojnarowska
- Institute of Physics, University of Silesia , Uniwersytecka 4, 40-007 Katowice, Poland
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40
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Kim SY, Lee J, Park MJ. Proton Hopping and Diffusion Behavior of Sulfonated Block Copolymers Containing Ionic Liquids. Macromolecules 2014. [DOI: 10.1021/ma4025152] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Sung Yeon Kim
- Division of Advanced Materials
Science and ‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea 790-784
| | - Joungphil Lee
- Division of Advanced Materials
Science and ‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea 790-784
| | - Moon Jeong Park
- Division of Advanced Materials
Science and ‡Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea 790-784
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41
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Park MJ, Choi I, Hong J, Kim O. Polymer electrolytes integrated with ionic liquids for future electrochemical devices. J Appl Polym Sci 2013. [DOI: 10.1002/app.39064] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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