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Fujii K, Kimura Y. Solvent Role of Ionic Liquids in Fundamental Chemical Reaction Dynamics Analyzed by Time-Resolved Spectroscopy. CHEM REC 2023; 23:e202200242. [PMID: 36634996 DOI: 10.1002/tcr.202200242] [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: 10/21/2022] [Revised: 12/24/2022] [Indexed: 01/14/2023]
Abstract
Ionic liquids (ILs), which are used as solvents for chemical reactions, are different from conventional organic solvents owing to their designability. Physicochemical parameters of the ILs, such as polarity and viscosity, that affect chemical equilibria and reaction kinetics can be tuned by changing the combination of anions and cations or by varying the lengths of the alkyl chains present in the cations. We were interested in knowing how these physicochemical parameters affect fundamental chemical reactions in ILs. Therefore, in this personal account, we investigate our recent work on two different photochemical reactions in ILs, namely excited-state intramolecular proton transfer of hydroxyflavone and photodissociation of aminodisulfide, using time-resolved spectroscopic techniques. Interestingly, the roles of the ILs in these chemical reactions are quite different. The effect of the cationic species of the ILs (i. e., the head groups and number of alkyl carbons) on the solvation environment upon photoexcitation and reaction rate are discussed.
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Affiliation(s)
- Kaori Fujii
- Faculty of Science and Engineering, Doshisha University, Kyotanabe-city, Kyoto 610-0321, Japan
| | - Yoshifumi Kimura
- Graduate School of Science and Engineering, Faculty of Science and Engineering, Doshisha University, Kyotanabe-city, Kyoto 610-0321, Japan
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2
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Michelarakis N, Franz F, Gkagkas K, Gräter F. Longitudinal strand ordering leads to shear thinning in Nafion. Phys Chem Chem Phys 2021; 23:25901-25910. [PMID: 34779459 DOI: 10.1039/d1cp02024b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Proton-exchange membrane fuel cells (PEMFC) offer a promising energy generation alternative for a wide range of technologies thanks to their ecological friendliness and unparalleled efficiency. At the heart of these electrochemical cells lies the membrane electrode assembly with its most important energy conversion components, the Proton Exchange Membrane. This component is created through the use of printing techniques and Nafion inks. The physicochemical properties of the ink, such as its viscosity under shear, are critical for the finished product. In this work we present non-equilibrium Molecular Dynamics simulations using a MARTINI based coarse-grained model for Nafion to understand the mechanism governing the shear viscosity of Nafion solutions. By simulating a Couette flow and calculating density maps of the Nafion chains in these simulations we shed light on the process that leads to the experimentally observed shear thinning effects of Nafion solutions under flow. We observe rod-shaped Nafion microstructures, 3 nm in size on average, when shear flow is absent or low. Higher shear rates instead break these structures and align Nafion strands along the direction of the flow, resulting in lower shear viscosities. Our work paves the way for a deeper understanding of the dynamic and mechanical properties of Nafion including studies of more complex CL and PEM inks.
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Affiliation(s)
- Nicholas Michelarakis
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Florian Franz
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Konstantinos Gkagkas
- Toyota Motor Europe, Technical Center, Toyota Motor Europe NVSA, Zavente, Belgium
| | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Interdisciplinary Center for Scientific Computing, Heidelberg University, INF 205, 69120 Heidelberg, Germany
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3
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Sheoran N, Boland B, Thornton S, Bochinski JR, Clarke LI. Increasing ionic conductivity within thermoplastics via commercial additives results in a dramatic decrease in fiber diameter from melt electrospinning. SOFT MATTER 2021; 17:9264-9279. [PMID: 34553740 DOI: 10.1039/d1sm01101d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Polyethylene melt conductivity was increased by adding a commercial anti-static agent, which resulted in a 20× decrease in electrospun fiber diameter and formation of a significant fraction of sub-micron diameter fibers. Two polyethylene formulations and varying additive concentrations were utilized to span the parameter space of conductivity and viscosity. The key role of conductivity in determining the jet radius (which sets the upper limit on the fiber size) is discussed in the context of fluid mechanics theory and previous simulations. Parameters which affect the conversion of the liquid jet to a solid fiber and the pertinent theory are outlined. An "unconfined" experimental configuration is utilized to both avoid potential needle clogging and enable direct observation of important characteristic length scales related to the interaction of the fluid and the applied electric field. In this approach, the fluid spontaneously forms an array of cone perturbations which act as stationary "nozzles" through which the mobile fluid flows to form the jet. The experimental data and theory considerations allow for a holistic discussion of the interaction between flow rate, viscosity, conductivity, and the resultant jet and fiber size. Information about the fluid viscosity and conductivity gained by observing the electrospinning process is highlighted. Schemes for theoretically predicting the cone-jet density, cone size, and flow rate are compared to experimental results.
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Affiliation(s)
- Neelam Sheoran
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA.
| | - Brent Boland
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA.
| | - Samuel Thornton
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA.
| | - Jason R Bochinski
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA.
| | - Laura I Clarke
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA.
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Preparation of Re-Dispersible Metal-Oxide Nanocomposite Particles Using Ionomers with Different EW for Enhanced Radical Scavenging Performance. Macromol Res 2021. [DOI: 10.1007/s13233-021-9068-6] [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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Fujii K, Yagi T, Nakano H, Sato H, Kimura Y. Experimental and theoretical study on p-aminophenylthyil radical geminate recombination in ionic liquids; analysis using the Smoluchowski-Collins-Kimball equation. J Chem Phys 2021; 154:154504. [PMID: 33887928 DOI: 10.1063/5.0047663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recombination dynamics of geminate p-aminophenylthiyl (PAPT) radicals produced from the photodissociation of bis(p-aminophenyl) disulfide in ionic liquids (ILs) were investigated by transient absorption spectroscopy. ILs with various cationic species were used to examine the effect of viscosity and polarity on recombination dynamics. Experimentally obtained recombination yields and dynamics were found to be virtually independent of the cation species, despite the viscosity range of the solvent ILs being extensive, spanning from a few tens of mPa s to several hundred mPa s. We applied a theoretical analysis model based on the diffusion equation to the time profiles of the experimentally determined recombination yields of geminate PAPT radicals. The square well potential was incorporated into the diffusion equation to consider the concerted dynamics of solvent cage formation and recombination. A long-time asymptotic expression for the survival probability of the photodissociated products was derived and used to simulate the experimentally obtained time profile of the recombination yield. The time profiles in the range of 20-1000 ps and the final yield were successfully simulated by the asymptotic expression of the square well potential model. The optimized parameters used for the fit, including the mutual diffusion coefficient of the radical pairs, cage radius of the potential well, and well depth, were discussed in terms of the diffusion coefficient conventional theory and the potential mean force estimated from the molecular dynamics simulation for the photodissociation reaction in ILs.
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Affiliation(s)
- Kaori Fujii
- Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
| | - Tomoaki Yagi
- Department of Molecular Engineering, Kyoto University, Kyoto Daigaku Katsura, Kyoto 615-8510, Japan
| | - Hiroshi Nakano
- Department of Molecular Engineering, Kyoto University, Kyoto Daigaku Katsura, Kyoto 615-8510, Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Kyoto University, Kyoto Daigaku Katsura, Kyoto 615-8510, Japan
| | - Yoshifumi Kimura
- Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
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Piednoir A, Steinberger A, Cottin-Bizonne C, Barentin C. Apparent Non-Newtonian Behavior of Ionic Liquids. J Phys Chem B 2020; 124:2685-2690. [PMID: 32134264 DOI: 10.1021/acs.jpcb.0c01760] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A significant viscosity variation with the shear rate has been observed for several ionic liquids in rheometry experiments above a critical shear rate. Depending on the liquid and the rheological conditions, both viscosity increase and decrease have been reported. So far, these variations have been interpreted as a signature of a non-Newtonian behavior. However, the measured critical shear rates are orders of magnitude below the ones predicted by numerical simulations. In this work, we perform new rheometry experiments with both ionic liquids and Newtonian liquids to elucidate this discrepancy. For these two types of liquids, both a viscosity decrease and increase have been measured depending on the geometry of the rheometer and the zero-shear viscosity of the liquid. We interpret the viscosity decrease as resulting from viscous heating, since the viscosity of the investigated liquids is also highly temperature-dependent, and the viscosity increase as resulting from the development of instabilities at high shear rates.
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Affiliation(s)
- Agnès Piednoir
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - Audrey Steinberger
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS, Laboratoire de Physique, 69364 Lyon, France
| | - Cécile Cottin-Bizonne
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - Catherine Barentin
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
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Mabuchi T, Huang S, Tokumasu T. Nafion Ionomer Dispersion in Mixtures of 1‐Propanol and Water Based on the Martini Coarse‐Grained Model. JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1002/pol.20190101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary SciencesTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
| | - Sheng‐Feng Huang
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
| | - Takashi Tokumasu
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
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Nakamura I, Shock CJ, Eggart L, Gao T. Theoretical Aspects of Ionic Liquids for Soft‐Matter Sciences. Isr J Chem 2018. [DOI: 10.1002/ijch.201800143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Issei Nakamura
- Department of PhysicsMichigan Technological University Houghton MI 49931 USA
| | - Cameron J. Shock
- Department of PhysicsMichigan Technological University Houghton MI 49931 USA
| | - Lisa Eggart
- Department of PhysicsMichigan Technological University Houghton MI 49931 USA
| | - Tong Gao
- Department of PhysicsMichigan Technological University Houghton MI 49931 USA
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Thoma M, Lin W, Hoffmann E, Sattes MM, Segets D, Damm C, Peukert W. Simple and Reliable Method for Studying the Adsorption Behavior of Aquivion Ionomers on Carbon Black Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:12324-12334. [PMID: 30234996 DOI: 10.1021/acs.langmuir.8b02726] [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
A better understanding of the interactions of carbon black and perfluorinated sulfonic acid (PFSA) ionomer helps to improve the effectiveness of polymer electrolyte membrane fuel cells. We present a simple and fast method for quantitative PFSA ionomer analysis based on suspension density measurements. After validation of the reliability of our method by thermogravimetric analysis and isothermal titration calorimetry (ITC), we investigate the adsorption equilibrium of short-side-chain PFSA ionomers of different equivalent weights (EW) and polarities on carbon black. The measured adsorption isotherms exhibit a plateau in the ionomer surface concentration for ionomer equilibrium concentrations ≤2 g/L. In this concentration range, the adsorption isotherms are described by the Langmuir model, whereby the surface concentrations in the plateau region are between 0.041 and 0.070 g/g. The plateau value of the ionomer surface concentration increases with EW and therefore with decreasing number of side chains with terminal sulfonic acid group per ionomer molecule, while the amount of adsorbed sulfonic acid groups remains constant for all investigated ionomers, resulting in similar ζ-potentials and sedimentation stability of the suspensions. The free energies of adsorption Δ G calculated from the association constants of the adsorption isotherms agree well with Δ G values obtained by isothermal titration calorimetry (ITC) and thus validate the adsorption isotherm measurement method. From the values of adsorption enthalpy Δ H ((-7.3 ± 0.8) kJ/mol) and entropy Δ S (ca. 100 J/(mol K)), which were extracted from ITC, we conclude that the ionomer adsorption on carbon black is a spontaneous physisorption process.
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Affiliation(s)
- Martin Thoma
- Institute of Particle Technology (LFG) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Cauerstraße 4 , D-91058 Erlangen , Germany
- Interdisciplinary Center for Functional Particle Systems (FPS) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Haberstraße 9a , D-90158 Erlangen , Germany
| | - Wei Lin
- Institute of Particle Technology (LFG) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Cauerstraße 4 , D-91058 Erlangen , Germany
- Interdisciplinary Center for Functional Particle Systems (FPS) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Haberstraße 9a , D-90158 Erlangen , Germany
| | - Eva Hoffmann
- Institute of Particle Technology (LFG) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Cauerstraße 4 , D-91058 Erlangen , Germany
- Interdisciplinary Center for Functional Particle Systems (FPS) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Haberstraße 9a , D-90158 Erlangen , Germany
| | - Maria-Melanie Sattes
- Institute of Particle Technology (LFG) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Cauerstraße 4 , D-91058 Erlangen , Germany
- Interdisciplinary Center for Functional Particle Systems (FPS) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Haberstraße 9a , D-90158 Erlangen , Germany
| | - Doris Segets
- Institute of Particle Technology (LFG) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Cauerstraße 4 , D-91058 Erlangen , Germany
- Interdisciplinary Center for Functional Particle Systems (FPS) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Haberstraße 9a , D-90158 Erlangen , Germany
| | - Cornelia Damm
- Institute of Particle Technology (LFG) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Cauerstraße 4 , D-91058 Erlangen , Germany
- Interdisciplinary Center for Functional Particle Systems (FPS) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Haberstraße 9a , D-90158 Erlangen , Germany
| | - Wolfgang Peukert
- Institute of Particle Technology (LFG) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Cauerstraße 4 , D-91058 Erlangen , Germany
- Interdisciplinary Center for Functional Particle Systems (FPS) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Haberstraße 9a , D-90158 Erlangen , Germany
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Nemoto F, Kofu M, Nagao M, Ohishi K, Takata SI, Suzuki JI, Yamada T, Shibata K, Ueki T, Kitazawa Y, Watanabe M, Yamamuro O. Neutron scattering studies on short- and long-range layer structures and related dynamics in imidazolium-based ionic liquids. J Chem Phys 2018; 149:054502. [PMID: 30089384 DOI: 10.1063/1.5037217] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Alkyl-methyl-imidazolium ionic liquids CnmimX (n: alkyl-carbon number, X: anion) have short-range layer structures consisting of ionic and neutral (alkylchain) domains. To investigate the temperature dependences of the interlayer, interionic group, and inter-alkylchain correlations, we have measured the neutron diffraction (ND) of C16mimPF6, C9.5mimPF6, and C8mimPF6 in the temperature region from 4 K to 470 K. The quasielastic neutron scattering (QENS) of C16mimPF6 was also measured to study the dynamics of each correlation. C16mimPF6 shows a first-order transition between the liquid (L) and liquid crystalline (LC) phases at Tc = 394 K. C8mimPF6 exhibits a glass transition at Tg = 200 K. C9.5mimPF6, which is a 1:3 mixture between C8mimPF6 and C10mimPF6, has both transitions at Tc = 225 K and Tg = 203 K. In the ND experiments, all samples exhibit three peaks corresponding to the correlations mentioned above. The widths of the interlayer peak at ca. 0.2 Å-1 changed drastically at the L-LC transitions, while the interionic peaks at ca. 1 Å-1 exhibited a small jump at Tc. The peak position and area of the three peaks did not change much at the transition. The structural changes were minimal at Tg. The QENS experiments demonstrated that the relaxation time of the interlayer motion increased tenfold at Tc, while those of other motions were monotonous in the whole temperature region. The structural and dynamical changes mentioned above are characteristic of the L-LC transition in imidazolium-based ionic liquids.
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Affiliation(s)
- Fumiya Nemoto
- Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Maiko Kofu
- Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Michihiro Nagao
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - Kazuki Ohishi
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), IQBRC Bldg., 162-1 Shirakata, Tokai, Naka, Ibaraki 319-1106, Japan
| | - Shin-Ichi Takata
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka, Ibaraki 319-1195, Japan
| | - Jun-Ichi Suzuki
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), IQBRC Bldg., 162-1 Shirakata, Tokai, Naka, Ibaraki 319-1106, Japan
| | - Takeshi Yamada
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), IQBRC Bldg., 162-1 Shirakata, Tokai, Naka, Ibaraki 319-1106, Japan
| | - Kaoru Shibata
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka, Ibaraki 319-1195, Japan
| | - Takeshi Ueki
- Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
| | - Yuzo Kitazawa
- Department of Chemistry and Biotechnology, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama, Kanagawa 240-8501, Japan
| | - Masayoshi Watanabe
- Department of Chemistry and Biotechnology, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama, Kanagawa 240-8501, Japan
| | - Osamu Yamamuro
- Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
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Lee JH, Doo G, Kwon SH, Choi S, Kim HT, Lee SG. Dispersion-Solvent Control of Ionomer Aggregation in a Polymer Electrolyte Membrane Fuel Cell. Sci Rep 2018; 8:10739. [PMID: 30013087 PMCID: PMC6048106 DOI: 10.1038/s41598-018-28779-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/19/2018] [Indexed: 11/09/2022] Open
Abstract
In this study, we examined the influence of the dispersion solvent in three dipropylene-glycol/water (DPG/water) mixtures, with DPG contents of 0, 50, and 100 wt%, on ionomer morphology and distribution, using dynamic light scattering (DLS) and molecular-dynamics (MD) simulation techniques. The DLS results reveal that Nafion-ionomer aggregation increases with decreasing DPG content of the solvent. Increasing the proportion of water in the solvent also led to a gradual decrease in the radius of gyration (Rg) of the Nafion ionomer due to its strong backbone hydrophobicity. Correspondingly, MD simulations predict Nafion-ionomer solvation energies of -147 ± 9 kcal/mol in water, -216 ± 21 kcal/mol in the DPG/water mixture, and -444 ± 9 kcal/mol in DPG. These results suggest that higher water contents in mixed DPG/water solvents result in increased Nafion-ionomer aggregation and the subsequent deterioration of its uniform dispersion in the solvent. Moreover, radial distribution functions (RDFs) reveal that the (-CF2CF2-) backbones of the Nafion ionomer are primarily enclosed by DPG molecules, whereas the sulfonate groups (SO3-) of its side chains mostly interact with water molecules.
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Affiliation(s)
- Ji Hye Lee
- Department of Organic Material Science and Engineering, Pusan National University, 2, Busandaehak-ro 63beon gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Gisu Doo
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Sung Hyun Kwon
- Department of Organic Material Science and Engineering, Pusan National University, 2, Busandaehak-ro 63beon gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Sungyu Choi
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hee-Tak Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
- Advanced Battery Center, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Seung Geol Lee
- Department of Organic Material Science and Engineering, Pusan National University, 2, Busandaehak-ro 63beon gil, Geumjeong-gu, Busan, 46241, Republic of Korea.
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Wawra SE, Thoma M, Walter J, Lübbert C, Thajudeen T, Damm C, Peukert W. Ionomer and protein size analysis by analytical ultracentrifugation and electrospray scanning mobility particle sizer. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 47:777-787. [PMID: 29909434 DOI: 10.1007/s00249-018-1314-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 04/17/2018] [Accepted: 06/07/2018] [Indexed: 11/25/2022]
Abstract
By combining analytical ultracentrifugation (AUC) in liquid phase and scanning mobility particle sizer (SMPS) in the gas phase, additional information on the particle size and morphology has been obtained for rigid particles. In this paper, we transfer this concept to soft particles, allowing us to analyze the size and molar mass of the short side chain perfluorosulfonic acid ionomer Aquivion® in a dilute aqueous suspension. The determination of the primary size and exact molar mass of this class of polymers is challenging since they are optically transparent and due to the formation of different aggregate structures depending on the concentration and solvent properties. First, validation of AUC and SMPS measurements was carried out using the well-defined biopolymers bovine serum albumin (BSA) and lysozyme (LYZ) to confirm the reliability of the results of the two unique and independent classifying methods. Then, the ionomer Aquivion® was studied using both techniques. From the mean molar mass of 185 ± 14 kDa obtained by AUC, a mean hydrodynamic diameter of 7.6 ± 0.5 nm was calculated. The particle size obtained from SMPS (7.1 nm) agrees very well with the results from AUC showing that the molecule was transferred into the gas phase without significantly changing its structure. In conclusion, the Aquivion® is molecularly dispersed in the used aqueous buffer solution without any aggregate formation in the investigated concentration range (< 2 g l-1).
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Affiliation(s)
- Simon E Wawra
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany
| | - Martin Thoma
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany
| | - Johannes Walter
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany
- Interdisciplinary Center for Functional Particle Systems (FPS), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Haberstrasse 9a, 91058, Erlangen, Germany
| | - Christian Lübbert
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany
- Interdisciplinary Center for Functional Particle Systems (FPS), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Haberstrasse 9a, 91058, Erlangen, Germany
| | - Thaseem Thajudeen
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany
- Interdisciplinary Center for Functional Particle Systems (FPS), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Haberstrasse 9a, 91058, Erlangen, Germany
- School of Mechanical Sciences, Indian Institute of Technology Goa, Ponda, 403401, India
| | - Cornelia Damm
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany
| | - Wolfgang Peukert
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany.
- Interdisciplinary Center for Functional Particle Systems (FPS), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Haberstrasse 9a, 91058, Erlangen, Germany.
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Jablonskas D, Ivanov M, Banys J, Giffin GA, Passerini S. Dielectric spectroscopy of Pyr14TFSI and Pyr12O1TFSI ionic liquids. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.04.104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Yang H, Li X, Batchelor-McAuley C, Sokolov SV, Kätelhön E, Compton RG. Immobilised Electrocatalysts: Nafion Particles Doped with Ruthenium(II) Tris(2,2'-bipyridyl). Chemistry 2017; 23:17605-17611. [PMID: 29034523 DOI: 10.1002/chem.201704418] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Indexed: 12/18/2022]
Abstract
Nafion particles doped with ruthenium(II) tris(2,2'-bipyridyl) are synthesized by using a re-precipitation method. Characterization including SEM sizing and quantification of Ru(bpy)32+ in the Nafion particles using UV/Vis spectroscopy was conducted. The synthesized Ru-Nafion particles were investigated electrochemically at both ensemble and single particle levels. Voltammetry of the drop-cast Ru-Nafion particles evidences the successful incorporation of Ru(bpy)32+ into the Nafion particle but only a small fraction of the incorporated Ru(bpy)32+ was detected due at least in part to the formation of the likely agglomerated and irregular "mat" associated with the dropcast technique. In contrast, nano-impact experiments provided a quantitative determination of the amount of Ru(bpy)32+ in single Ru-Nafion particles. Finally, oxidation of solution-phase oxalate mediated by Ru(bpy)32+ within individual Nafion particles was observed, showing the electrocatalytic properties of the Ru-Nafion particles.
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Affiliation(s)
- Haiying Yang
- Department of Chemistry, Yuncheng University, Yuncheng, 044000, P.R. China.,Department of Chemistry, Physical & Theoretical Chemistry Laboratory, Oxford University, Oxford, OX1 3QZ, UK
| | - Xiuting Li
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, Oxford University, Oxford, OX1 3QZ, UK
| | | | - Stanislav V Sokolov
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, Oxford University, Oxford, OX1 3QZ, UK
| | - Enno Kätelhön
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, Oxford University, Oxford, OX1 3QZ, UK
| | - Richard G Compton
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, Oxford University, Oxford, OX1 3QZ, UK
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15
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Zorębski E, Zorębski M, Musiał M, Dzida M. Ultrasonic Relaxation Spectra for Pyrrolidinium Bis(trifluoromethylsulfonyl)imides: A Comparison with Imidazolium Bis(trifluoromethylsulfonyl)imides. J Phys Chem B 2017; 121:9886-9894. [PMID: 28950058 DOI: 10.1021/acs.jpcb.7b07433] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ultrasound absorption spectra within the frequency range 10-300 MHz were determined for 1-propyl- and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imides at ambient pressure and at temperatures in the ranges 293.15-313.15 and 293.15-323.15 K, respectively. For both compounds, a single Debye model (relaxation times between 0.451 and 0.778 ns) thoroughly describes the observed ultrasound absorption spectra in the investigated ranges. The spectra resemble those observed for imidazolium-based ionic liquids with the same anion. The ultrasound relaxation is dependent on the alkyl chain length of pyrrolidinium ring. In comparison to adequate imidazolium-based bis(trifluoromethylsulfonyl)imides, the relaxation in pyrrolidinium-based bis(trifluoromethylsulfonyl)imides is stronger; the pyrrolidinium cation causes clearly greater absorption than the imidazolium cation. Also, estimated ultrasound velocity dispersion is stronger in the case of pyrrolidinium imides in comparison to imidazolium imides. In turn, comparison of the ultrasonic data and literature data for the dielectric spectra exemplified for the 1-butyl- side chain in the cation indicates strong coupling in the case of imidazolium ring and weak coupling in the case of pyrrolidinium ring. The effect of absorption on the speed of sound is also discussed.
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Affiliation(s)
- Edward Zorębski
- Institute of Chemistry, University of Silesia , Szkolna 9, 40-006 Katowice, Poland
| | - Michał Zorębski
- Institute of Chemistry, University of Silesia , Szkolna 9, 40-006 Katowice, Poland
| | - Małgorzata Musiał
- Institute of Chemistry, University of Silesia , Szkolna 9, 40-006 Katowice, Poland
| | - Marzena Dzida
- Institute of Chemistry, University of Silesia , Szkolna 9, 40-006 Katowice, Poland
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16
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Mima T, Kinjo T, Yamakawa S, Asahi R. Study of the conformation of polyelectrolyte aggregates using coarse-grained molecular dynamics simulations. SOFT MATTER 2017; 13:5991-5999. [PMID: 28776057 DOI: 10.1039/c7sm01196b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The conformation of polyelectrolyte aggregates as a function of the backbone rigidity is investigated by coarse-grained molecular dynamics simulation. The polyelectrolyte is represented by a bead-spring chain with charged side chains. The simulations start from the uniform distributions of the polyelectrolytes, and the resultant polyelectrolyte conformation after a few microseconds exhibits spherical self-aggregates, clusters, or bending bundle-like aggregates, depending on the backbone rigidity. The interaggregate structures on a large scale are featured by the static structure factor (SSF). The simulated SSFs of the bending bundle-like aggregates are consistent with those of the small angle X-ray scattering (SAXS) measurement so we successfully assign the microscopic structures of polyelectrolytes to the SAXS measurement. The power-law of the SSFs for the bundle conditions is steeper than that of the conventional cylinder model. The present study finds that such discrepancy in the power-law results from the bending of the bundle-like aggregates. In addition, the relaxation behavior includes slow dynamics. The present study proposes that such slow dynamics results from diffusion-limited aggregation and from gliding processes to reduce local metastable folding within the aggregates.
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Affiliation(s)
- Toshiki Mima
- Toyota Central R&D Labs., Inc., 41-1, Yokomichi, Nagakute, Aichi, Japan.
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17
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Takahashi S, Shimanuki J, Mashio T, Ohma A, Tohma H, Ishihara A, Ito Y, Nishino Y, Miyazawa A. Observation of ionomer in catalyst ink of polymer electrolyte fuel cell using cryogenic transmission electron microscopy. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.12.068] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Yamaguchi T. Mode-coupling theoretical study on the roles of heterogeneous structure in rheology of ionic liquids. J Chem Phys 2016; 144:124514. [PMID: 27036468 DOI: 10.1063/1.4944679] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Theoretical calculations of the rheological properties of coarse-grained model ionic liquids were performed using mode-coupling theory. The nonpolar part of the cation was systematically increased in order to clarify the effects of the heterogeneous structure on shear viscosity. The shear viscosity showed a minimum as the function of the size of the nonpolar part, as had been reported in literatures. The minimum was ascribed to the interplay between the increase in the shear relaxation time and the decrease in the high-frequency shear modulus with increasing the size of the nonpolar part of the cation. The ionic liquids with symmetric charge distribution of cations were less viscous than those with asymmetric cations, which is also in harmony with experiments. The theoretical analysis demonstrated that there are two mechanisms for the higher viscosity of the asymmetric model. The first one is the direct coupling between the domain dynamics and the shear stress. The second one is that the microscopic dynamics within the polar domain is retarded due to the nonlinear coupling with the heterogeneous structure.
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Affiliation(s)
- Tsuyoshi Yamaguchi
- Department of Molecular Design and Engineering, Graduate School of Engineering, Furo-cho B2-3 (611), Chikusa, Nagoya, Aichi 464-8603, Japan
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19
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Ortaboy S. Electropolymerization of aniline in phosphonium-based ionic liquids and their application as protective films against corrosion. J Appl Polym Sci 2016. [DOI: 10.1002/app.43923] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Sinem Ortaboy
- Department of Chemistry, Engineering Faculty; Istanbul University; Avcılar Istanbul Turkey
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20
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Zorębski M, Zorębski E, Dzida M, Skowronek J, Jężak S, Goodrich P, Jacquemin J. Ultrasonic Relaxation Study of 1-Alkyl-3-methylimidazolium-Based Room-Temperature Ionic Liquids: Probing the Role of Alkyl Chain Length in the Cation. J Phys Chem B 2016; 120:3569-81. [DOI: 10.1021/acs.jpcb.5b12635] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michał Zorębski
- Institute
of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland
| | - Edward Zorębski
- Institute
of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland
| | - Marzena Dzida
- Institute
of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland
| | - Justyna Skowronek
- Institute
of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland
| | - Sylwia Jężak
- Institute
of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland
| | - Peter Goodrich
- QUILL
Research Centre, Queen’s University of Belfast, BT95AG Belfast, Northern Ireland United Kingdom
| | - Johan Jacquemin
- QUILL
Research Centre, Queen’s University of Belfast, BT95AG Belfast, Northern Ireland United Kingdom
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21
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Yamaguchi T, Yonezawa T, Yoshida K, Yamaguchi T, Nagao M, Faraone A, Seki S. Relationship between Structural Relaxation, Shear Viscosity, and Ionic Conduction of LiPF6/Propylene Carbonate Solutions. J Phys Chem B 2015; 119:15675-82. [DOI: 10.1021/acs.jpcb.5b08701] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tsuyoshi Yamaguchi
- Department of Molecular Design and Engineering, Graduate
School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi 464-8603, Japan
| | - Takuya Yonezawa
- Department of Molecular Design and Engineering, Graduate
School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi 464-8603, Japan
| | - Koji Yoshida
- Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan, Fukuoka 814-0180, Japan
| | - Toshio Yamaguchi
- Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan, Fukuoka 814-0180, Japan
| | - Michihiro Nagao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
- Center
for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408-1398, United States
| | - Antonio Faraone
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
| | - Shiro Seki
- Materials Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1, Iwado-kita, Komae, Tokyo 201-8511, Japan
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22
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Palumbo O, Trequattrini F, Vitucci FM, Paolone A. Relaxation Dynamics and Phase Transitions in Ionic Liquids: Viscoelastic Properties from the Liquid to the Solid State. J Phys Chem B 2015; 119:12905-11. [DOI: 10.1021/acs.jpcb.5b06039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- O. Palumbo
- CNR-ISC, U.O.S. La Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy
| | - F. Trequattrini
- Physics
Department, Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy
| | - F. M. Vitucci
- CNR-ISC, U.O.S. La Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy
| | - A. Paolone
- CNR-ISC, U.O.S. La Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy
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23
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Yamaguchi T, Yonezawa T, Koda S. Study on the temperature-dependent coupling among viscosity, conductivity and structural relaxation of ionic liquids. Phys Chem Chem Phys 2015; 17:19126-33. [DOI: 10.1039/c5cp02335a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The frequency-dependent viscosity and conductivity of three imidazolium-based ionic liquids were measured at several temperatures in the MHz region, and the results are compared with the intermediate scattering functions determined by neutron spin echo spectroscopy.
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Affiliation(s)
- Tsuyoshi Yamaguchi
- Department of Molecular Design and Engineering
- Graduate School of Engineering
- Nagoya University
- Nagoya
- Japan
| | - Takuya Yonezawa
- Department of Molecular Design and Engineering
- Graduate School of Engineering
- Nagoya University
- Nagoya
- Japan
| | - Shinobu Koda
- Department of Molecular Design and Engineering
- Graduate School of Engineering
- Nagoya University
- Nagoya
- Japan
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24
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Yamaguchi T, Koda S. Dielectric and shear relaxations of ionic liquid composed of symmetric ions. J Chem Phys 2014; 141:144503. [DOI: 10.1063/1.4897988] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Tsuyoshi Yamaguchi
- Department of Molecular Design and Engineering, Graduate School of Engineering, Furo-cho B2-3 (611), Chikusa, Nagoya, Aichi 464-8603, Japan
| | - Shinobu Koda
- Department of Molecular Design and Engineering, Graduate School of Engineering, Furo-cho B2-3 (611), Chikusa, Nagoya, Aichi 464-8603, Japan
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