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Eliasen KL, Gabriel J, Blochowicz T, Gainaru CP, Christensen TE, Niss K. What is the origin of slow relaxation modes in highly viscous ionic liquids? J Chem Phys 2024; 161:034506. [PMID: 39012811 DOI: 10.1063/5.0215661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Accepted: 06/27/2024] [Indexed: 07/18/2024] Open
Abstract
Room temperature ionic liquids (RTILs) are molten salts consisting entirely of ions and have over the past decades gained increased interest due to their high potential in applications. These structurally complex systems often display multiple relaxation modes in the response functions at lower frequencies, hinting to complex underlying mechanisms. While the existence of these multimodal spectra in the shear mechanical, dielectric, and light scattering response of RTILs has been confirmed multiple times, controversy still surrounds the origin. This paper, therefore, aims to provide additional insights into the multimodal spectra seen in RTILs by presenting new shear mechanical results on seven different RTILs: Pyr1n-TFSI with n = 4, 6, and 8; Pyr18-TFSI mixed with Li-TFSI in two high concentrations; and Cn-mim-BF4 with n = 3 and 8. Dynamic depolarized light scattering was also measured on one of the Pyr18-TFSI Li-salt mixtures. These specific cases were analyzed in detail and put into a bigger perspective together with an overview of the literature. Recent literature offers two specific explanations for the origin of the multimodal shear mechanical spectra: (1) cation-anion time scale separation or (2) combined cation-anion relaxation in addition to a dynamic signal from mesoscale aggregates at lower frequencies. However, neither of these two pictures can consistently explain all the results on different ionic liquids. Instead, we conclude that the origin of the multimodal spectrum is system specific. This underlines the complexity of this class of liquids and shows that great care must be taken when making general conclusions based on specific cases.
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Affiliation(s)
- Kira L Eliasen
- "Glass and Time," IMFUFA, Department of Science and Environment, Roskilde University, Roskilde 4000, Denmark
| | - Jan Gabriel
- "Glass and Time," IMFUFA, Department of Science and Environment, Roskilde University, Roskilde 4000, Denmark
| | - Thomas Blochowicz
- Institut für Festkörperphysik, Technische Universität Darmstadt, Darmstadt 64289, Germany
| | - Catalin P Gainaru
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Tage E Christensen
- "Glass and Time," IMFUFA, Department of Science and Environment, Roskilde University, Roskilde 4000, Denmark
| | - Kristine Niss
- "Glass and Time," IMFUFA, Department of Science and Environment, Roskilde University, Roskilde 4000, Denmark
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2
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Koymeth S, Yao B, Paluch M, Dulski M, Swadzba-Kwasny M, Wojnarowska Z. Inflection Point in Pressure Dependence of Ionic Conductivity as a Fingerprint of Local Structure Formation. J Phys Chem B 2024; 128:5109-5117. [PMID: 38718191 PMCID: PMC11129299 DOI: 10.1021/acs.jpcb.3c08506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 04/05/2024] [Accepted: 04/15/2024] [Indexed: 05/24/2024]
Abstract
In this study, we employed dielectric spectroscopy to investigate the effect of temperature and pressure on the ion dynamics of phosphonium ionic liquids (ILs) differing by the length of an alkyl chain, [P666,n][TFSI] (n = 2, 6, 8, 12). We found that both temperature and pressure dependence of dc-conductivity (σdc) determined for all examined ILs herein exhibit unique characteristics, unusual for aprotic ILs. Two regions differing by ion self-organization have been identified from the derivative analysis of σdc(T-1) data. On the other hand, isothermal measurements performed at elevated pressure revealed a unique concave-convex character of σdc(P) dependences, resulting in a clear minimum in the pressure behavior of activation volume. Such an inflection point characterizing the pressure dependence of σdc in [P666,n][TFSI] ILs can be considered an inherent feature of ion dynamics governed by structural self-assembly. Our results offer a unique perspective to link the ion mobility at various T-P conditions to the nanostructural organization of ionic systems.
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Affiliation(s)
- S. Koymeth
- Faculty
of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - B. Yao
- Faculty
of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - M. Paluch
- Faculty
of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - M. Dulski
- Faculty
of Science and Technology, Institute of Materials Science, University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - M. Swadzba-Kwasny
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Road, Belfast BT9 5AG, U.K.
| | - Z. Wojnarowska
- Faculty
of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
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3
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Stachurski CD, Davis JH, Cosby T, Crowley ME, Larm NE, Ballentine MG, O’Brien RA, Zeller M, Salter EA, Wierzbicki A, Trulove PC, Durkin DP. Physical and Electrochemical Analysis of N-Alkylpyrrolidinium-Substituted Boronium Ionic Liquids. Inorg Chem 2023; 62:18280-18289. [PMID: 37870915 PMCID: PMC10630938 DOI: 10.1021/acs.inorgchem.3c02971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Indexed: 10/24/2023]
Abstract
In this work, a series of novel boronium-bis(trifluoromethylsulfonyl)imide [TFSI-] ionic liquids (IL) are introduced and investigated. The boronium cations were designed with specific structural motifs that delivered improved electrochemical and physical properties, as evaluated through cyclic voltammetry, broadband dielectric spectroscopy, densitometry, thermogravimetric analysis, and differential scanning calorimetry. Boronium cations, which were appended with N-alkylpyrrolidinium substituents, exhibited superior physicochemical properties, including high conductivity, low viscosity, and electrochemical windows surpassing 6 V. Remarkably, the boronium ionic liquid functionalized with both an ethyl-substituted pyrrolidinium and trimethylamine, [(1-e-pyrr)N111BH2][TFSI], exhibited a 6.3 V window, surpassing previously published boronium-, pyrrolidinium-, and imidazolium-based IL electrolytes. Favorable physical properties and straightforward tunability make boronium ionic liquids promising candidates to replace conventional organic electrolytes for electrochemical applications requiring high voltages.
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Affiliation(s)
| | - James H. Davis
- Department
of Chemistry, University of South Alabama, Mobile, Alabama36688, United States
| | - Tyler Cosby
- School
of Mathematics and Sciences, University
of Tennessee Southern, Pulaski, Tennessee38478, United States
| | - Margaret E. Crowley
- Department
of Chemistry, University of South Alabama, Mobile, Alabama36688, United States
| | - Nathaniel E. Larm
- Department
of Chemistry, U.S. Naval Academy, Annapolis, Maryland21402, United States
| | - Mollie G. Ballentine
- Department
of Chemistry, University of South Alabama, Mobile, Alabama36688, United States
| | - Richard A. O’Brien
- Department
of Chemistry, University of South Alabama, Mobile, Alabama36688, United States
| | - Matthias Zeller
- Department
of Chemistry, Purdue University, West Lafayette, Indiana47907, United States
| | - E. Alan Salter
- Department
of Chemistry, University of South Alabama, Mobile, Alabama36688, United States
| | - Andrzej Wierzbicki
- Department
of Chemistry, University of South Alabama, Mobile, Alabama36688, United States
| | - Paul C. Trulove
- Department
of Chemistry, U.S. Naval Academy, Annapolis, Maryland21402, United States
| | - David P. Durkin
- Department
of Chemistry, U.S. Naval Academy, Annapolis, Maryland21402, United States
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4
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Cosby T, Stachurski CD, Mantz RA, Trulove PC, Durkin DP. Elucidating the interplay of local and mesoscale ion dynamics and transport properties in aprotic ionic liquids. Phys Chem Chem Phys 2023; 25:6342-6351. [PMID: 36779353 DOI: 10.1039/d2cp05863d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ion dynamics and charge transport in 1-methyl-3-octylimidazolium ionic liquids with chloride, bromide, tetrafluoroborate, tricyanomethanide, hexafluorophosphate, triflate, tetrachloroaluminate, bis(trifluoromethylsulfonyl)imide, and heptachlorodialuminate anions are investigated by broadband dielectric spectroscopy, rheology, viscometry, and differential scanning calorimetry. A detailed analysis reveals an anion and temperature-dependent separation of characteristic molecular relaxation rates extracted from various representations of the dielectric spectra. The separation in rates extracted from the electric modulus and conductivity formalisms is interpreted as an experimental signature of significant heterogeneity in the local ion dynamics associated with the structural glass transition, viscosity, and dc ion conductivity. It is further found that the degree of dynamic heterogeneity correlates with the strengths of slow dielectric and mechanical relaxations previously attributed to the dynamics of mesoscale solvophobic aggregates. Increasing local dynamic heterogeneity correlates with an increase in the strength of the slow, aggregate dielectric relaxation and a decrease in the strength of the slow, aggregate mechanical relaxation. Accordingly, increasing local dynamic heterogeneity, brought about by change in temperature and/or cation/anion chemical structure, correlates with an increase in the static dielectric permittivities and a decrease in the contribution of aggregate dynamics to the zero-shear viscosities. The established correlation provides a new ability to distinguish between the influence of mesoscale aggregate shape/morphology versus local and mesoscale ion dynamics on the transport properties of ionic liquids.
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Affiliation(s)
- Tyler Cosby
- Division of Mathematics and Sciences, University of Tennessee Southern, Pulaski, TN, USA.
| | | | | | - Paul C Trulove
- Department of Chemistry, US Naval Academy, Annapolis, MD, USA.
| | - David P Durkin
- Department of Chemistry, US Naval Academy, Annapolis, MD, USA.
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5
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Pabst F, Blochowicz T. On the intensity of light scattered by molecular liquids-Comparison of experiment and quantum chemical calculations. J Chem Phys 2022; 157:244501. [PMID: 36586992 DOI: 10.1063/5.0133511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The intensity of light scattered by liquids has been studied for over a century since the valuable microscopic information about the molecules can be obtained, such as the anisotropy of the molecular polarizability tensor or preferred orientations of neighboring molecules. However, in modern dynamic light scattering experiments, the scattering intensity is usually disregarded, unlike in dielectric spectroscopy, which can be considered as a complementary experimental method, where the dielectric strength is routinely evaluated. The reason lies partly on the fact that the exact form of the equations relating the macroscopically measured light scattering intensity to the microscopic properties of the molecules is debated in the literature. Therefore, as a first step, we compare anisotropy parameters from the literature, calculated from light scattering intensities using different equations, with quantum chemical calculations for over 150 medium-sized molecules. This allows us to identify a consistent form of equations. In a second part, we turn to the depolarized light scattering spectra of 13 van der Waals liquids and some mixtures thereof, recorded with a combination of Tandem-Fabry-Perót and Raman spectroscopies, giving direct access to the reorientational dynamics of the molecules. We discuss how the strength of the structural α-relaxation is connected to the anisotropy parameter, what implication this has for the shape of the α-relaxation, how the components of a mixture-also for the case of ionic liquids-can be identified in this way, and how orientational correlation parameters can be extracted. Additionally, we point out for the example of n-alkanes that for highly flexible molecules, the reorientational motion might not be the decisive source of the depolarized scattered light. We also show that light scattering might serve as a sensitive tool to check the accuracy of a conformer ensemble obtained by quantum chemical calculations.
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Affiliation(s)
- Florian Pabst
- TU Darmstadt, Institute of Condensed Matter Physics, 64289 Darmstadt, Germany
| | - Thomas Blochowicz
- TU Darmstadt, Institute of Condensed Matter Physics, 64289 Darmstadt, Germany
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6
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Wang Y. Low-frequency dynamics in ionic liquids: Comparison of experiments and the random barrier model. Phys Chem Chem Phys 2022; 24:16501-16511. [DOI: 10.1039/d2cp01858f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By examining the fine features of dielectric spectra of ionic liquids, we show that the derivative of real permittivity progressively broadens at low frequencies when the glass transition is approached...
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7
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Hachuła B, Grelska J, Soszka N, Jurkiewicz K, Nowok A, Szeremeta A, Pawlus S, Paluch M, Kaminski K. Systematic studies on the dynamics, intermolecular interactions and local structure in the alkyl and phenyl substituted butanol isomers. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.117098] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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8
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Zhang X, Dai X, Han Q, Zhao J, Jing D, Liu F, Li L, Xin Y, Liu K. Prediction and New Insight for the Drag Reduction of Turbulent Flow with Polymers and Its Degradation Mechanism. J Phys Chem Lett 2021; 12:7201-7206. [PMID: 34310148 DOI: 10.1021/acs.jpclett.1c02027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A physicochemical understanding of the mechanism of turbulent flow drag reduction with polymer and its degradation is of great interest from both science and industry perspectives. Although the correlation based on the Fourier series has been proposed to predict the drag reduction and its degradation, its physical meaning was not clear until now. This letter aims to clarify this issue. We develop a comprehensive model to predict the drag reduction and degradation of polymers in turbulent flow from a chemical thermodynamics and kinetics viewpoint. We demonstrate that the Fourier series employed to predict the drag reduction and its degradation is due to the viscoelastic property of drag-reducing polymer solution, and the phase angle in the model, in physical nature, represents the hysteresis of the polymer in turbulent flow. Besides, our new insight of drag reduction with flexible polymers can also explain why a maximum drag reduction in rotational flow appears before degradation happens.
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Affiliation(s)
- Xin Zhang
- College of Petroleum Engineering, Shandong Institute of Petroleum and Chemical Technology, Dongying, Shandong 257061, People's Republic of China
| | - Xiaodong Dai
- College of Petroleum Engineering, Shandong Institute of Petroleum and Chemical Technology, Dongying, Shandong 257061, People's Republic of China
| | - Qiaorong Han
- Oil & Gas Technology Research Institute of Changqing Oilfield Company, Xi'an, Shaanxi 710018, People's Republic of China
| | - Jishi Zhao
- Yunfu (Foshan) R&D Center of Hydrogen Energy Standardization, Yunfu, Guangdong 527326, People's Republic of China
| | - Dengwei Jing
- State Key Laboratory of Multiphase Flow in Power Engineering & International Research Center for Renewable Energy, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, People's Republic of China
| | - Fei Liu
- College of Petroleum Engineering, Shandong Institute of Petroleum and Chemical Technology, Dongying, Shandong 257061, People's Republic of China
| | - Lei Li
- College of Petroleum Engineering, Shandong Institute of Petroleum and Chemical Technology, Dongying, Shandong 257061, People's Republic of China
| | - Yanping Xin
- College of Petroleum Engineering, Shandong Institute of Petroleum and Chemical Technology, Dongying, Shandong 257061, People's Republic of China
| | - Kun Liu
- College of Petroleum Engineering, Shandong Institute of Petroleum and Chemical Technology, Dongying, Shandong 257061, People's Republic of China
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9
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Affiliation(s)
- Swati Arora
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Julisa Rozon
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Jennifer E. Laaser
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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10
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Evidence of a liquid-liquid transition in a glass-forming ionic liquid. Proc Natl Acad Sci U S A 2021; 118:2020878118. [PMID: 33688049 DOI: 10.1073/pnas.2020878118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A liquid-liquid transition (LLT) is a transformation from one liquid to another through a first-order transition. The LLT is fundamental to the understanding of the liquid state and has been reported in a few materials such as silicon, phosphorus, triphenyl phosphite, and water. Furthermore, it has been suggested that the unique properties of materials such as water, which is critical for life on the planet, are linked to the existence of the LLT. However, the experimental evidence for the existence of an LLT in many molecular liquids remains controversial, due to the prevalence and high propensity of the materials to crystallize. Here, we show evidence of an LLT in a glass-forming trihexyltetradecylphosphonium borohydride ionic liquid that shows no tendency to crystallize under normal laboratory conditions. We observe a step-like increase in the static dielectric permittivity at the transition. Furthermore, the sizes of nonpolar local domains and ion-coordination numbers deduced from wide-angle X-ray scattering also change abruptly at the LLT. We independently corroborate these changes in local organization using Raman spectroscopy. The experimental access to the evolution of local order and structural dynamics across a liquid-liquid transition opens up unprecedented possibilities to understand the nature of the liquid state.
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11
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Mapesa EU, Cantillo NM, Hamilton ST, Harris MA, Zawodzinski TA, Alissa Park AH, Sangoro J. Localized and Collective Dynamics in Liquid-like Polyethylenimine-Based Nanoparticle Organic Hybrid Materials. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02370] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emmanuel Urandu Mapesa
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200, United States
| | - Nelly M. Cantillo
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200, United States
| | - Sara T. Hamilton
- Department of Earth and Environmental Engineering, Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, New York 10027-6699, United States
| | - Matthew A. Harris
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200, United States
| | - Thomas A. Zawodzinski
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200, United States
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Ah-Hyung Alissa Park
- Department of Earth and Environmental Engineering, Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, New York 10027-6699, United States
| | - Joshua Sangoro
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200, United States
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12
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Tu W, Jurkiewicz K, Adrjanowicz K. Confinement of pyrrolidinium-based ionic liquids [CnMPyrr]+[Tf2N]− with long cationic alkyl side chains (n = 10 and 16) to nanoscale pores: Dielectric and calorimetric studies. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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13
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Pabst F, Wojnarowska Z, Paluch M, Blochowicz T. On the temperature and pressure dependence of dielectric relaxation processes in ionic liquids. Phys Chem Chem Phys 2021; 23:14260-14275. [PMID: 34159979 DOI: 10.1039/d1cp01636a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular dynamics of ionic liquids in an electric field can be decomposed into contributions from translational motions of ions, rotational motions of permanent dipoles and - in the case of ions equipped with long alkyl-chains - motions of ionic aggregates. The discrimination of these contributions in the dielectric spectrum is quite involved, resulting in numerous controversies in the literature. Here, we use dielectric spectroscopy at ambient and elevated pressures of up to 550 MPa to monitor the changes of the observed processes in five supercooled ionic liquids with octyl-chains independent of pressure and temperature. In most of the ionic liquids under investigation two dynamical processes are observed, one of them is identified as the ion hopping process, which we describe by the MIGRATION model. It turns out that this process is closely connected to the glass transition step as measured by differential scanning calorimetry. Concerning the second process, we rule out motions of aggregated ions to be its origin by comparison of our results with X-ray scattering literature data at elevated pressure. Instead, we tentatively ascribe it to dipolar reorientations and show that the dielectric strength of this slow process decreases as a function of increasing relaxation time, i.e. for decreasing temperatures and increasing pressures. We compare this behavior with literature data of other ion conducting systems and discuss its microscopic origin.
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Affiliation(s)
- Florian Pabst
- TU Darmstadt, Institut für Physik kondensierter Materie, 64289 Darmstadt, Germany.
| | - Zaneta Wojnarowska
- Institute of Physics, University of Silesia in Katowice, SMCEBI, 75 Pulku Piechoty 1A, Chorzow 41-500, Poland
| | - Marian Paluch
- Institute of Physics, University of Silesia in Katowice, SMCEBI, 75 Pulku Piechoty 1A, Chorzow 41-500, Poland
| | - Thomas Blochowicz
- TU Darmstadt, Institut für Physik kondensierter Materie, 64289 Darmstadt, Germany.
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14
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Knapik-Kowalczuk J, Rams-Baron M, Paluch M. Current research trends in dielectric relaxation studies of amorphous pharmaceuticals: Physical stability, tautomerism, and the role of hydrogen bonding. Trends Analyt Chem 2021. [DOI: 10.1016/j.trac.2020.116097] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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15
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Musiał M, Cheng S, Wojnarowska Z, Yao B, Jurkiewicz K, Paluch M. Thorough studies of tricyanomethanide-based ionic liquids - the influence of alkyl chain length of the cation. SOFT MATTER 2020; 16:9479-9487. [PMID: 32955538 DOI: 10.1039/d0sm01433h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The glassy, supercooled, and normal liquid states of the 1-alkyl-3-methylimidazolium tricyanomethanide series [CnC1im][TCM] (n = 2, 4, 6, 8, and 16) were investigated by dielectric and mechanical (rheological) experiments supplemented by X-ray diffraction. The conductivity relaxation was found to be accompanied by a pronounced secondary relaxation. However, based on ambient and high-pressure results as well as the coupling model, we assumed that the latter one can not be classified as Johari-Goldstein relaxation. Moreover, the studies on the nanoscale organization of ionic liquids indicated that 1-alkyl-3-methylimidazolium tricyanomethanide ILs begin to form nanoscale aggregates when the alkyl chain of the cation has six carbon atoms.
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Affiliation(s)
- Małgorzata Musiał
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Shinian Cheng
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Zaneta Wojnarowska
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Beibei Yao
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Karolina Jurkiewicz
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Marian Paluch
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
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16
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Cosby T, Kapoor U, Shah JK, Sangoro J. Mesoscale Organization and Dynamics in Binary Ionic Liquid Mixtures. J Phys Chem Lett 2019; 10:6274-6280. [PMID: 31560210 DOI: 10.1021/acs.jpclett.9b02478] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The impact of mesoscale organization on dynamics and ion transport in binary ionic liquid mixtures is investigated by broad-band dielectric spectroscopy, dynamic-mechanical spectroscopy, X-ray scattering, and molecular dynamics simulations. The mixtures are found to form distinct liquids with macroscopic properties that significantly deviate from weighted contributions of the neat components. For instance, it is shown that the mesoscale morphologies in ionic liquids can be tuned by mixing to enhance the static dielectric permittivity of the resulting liquid by as high as 100% relative to the neat ionic liquid components. This enhancement is attributed to the intricate role of interfacial dynamics associated with the changes in the mesoscopic aggregate morphologies in these systems. These results demonstrate the potential to design the physicochemical properties of ionic liquids through control of solvophobic aggregation.
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Affiliation(s)
- Tyler Cosby
- Department of Chemical and Biomolecular Engineering , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Utkarsh Kapoor
- School of Chemical Engineering , Oklahoma State University , Stillwater , Oklahoma 74078 , United States
| | - Jindal K Shah
- School of Chemical Engineering , Oklahoma State University , Stillwater , Oklahoma 74078 , United States
| | - Joshua Sangoro
- Department of Chemical and Biomolecular Engineering , University of Tennessee , Knoxville , Tennessee 37996 , United States
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17
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Yamaguchi T. Shear Thinning and Nonlinear Structural Deformation of Ionic Liquids with Long Alkyl Chains Studied by Molecular Dynamics Simulation. J Phys Chem B 2019; 123:6260-6265. [PMID: 31259551 DOI: 10.1021/acs.jpcb.9b03557] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nonequilibrium molecular dynamics (MD) simulation was performed on imidazolium-based ionic liquids of two different alkyl chain lengths, and shear-rate-dependent viscosity was evaluated. Compared with the frequency-dependent linear shear viscosity determined by equilibrium MD simulation, shear thinning occurs at the shear rate several times lower than that predicted by the Cox-Merz rule. The deformation of the structure factor was also evaluated as the function of shear rate. The onset of shear thinning corresponds to that of the nonlinearity in the deformation of the charge-alternation mode in both ionic liquids, which is in harmony with the result of our previous work that the shear relaxation of ionic liquids is mainly coupled to the structural relaxation of the charge-alternation mode. In the presence of the polar-nonpolar domain structure characteristic to ionic liquids with a long alkyl chain, in particular, the nonlinearity in the domain mode begins within the Newtonian regime of shear viscosity.
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Affiliation(s)
- Tsuyoshi Yamaguchi
- Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa, Nagoya , Aichi 464-8603 , Japan
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18
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Huang J, Morin FJ, Laaser JE. Charge-Density-Dominated Phase Behavior and Viscoelasticity of Polyelectrolyte Complex Coacervates. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00036] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Jun Huang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Frances J. Morin
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Jennifer E. Laaser
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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19
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Pabst F, Gabriel J, Blochowicz T. Mesoscale Aggregates and Dynamic Asymmetry in Ionic Liquids: Evidence from Depolarized Dynamic Light Scattering. J Phys Chem Lett 2019; 10:2130-2134. [PMID: 30978281 DOI: 10.1021/acs.jpclett.9b00686] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Nanoscale structures in ionic liquids (ILs) are usually identified by X-ray or neutron scattering techniques and occur when the alkyl chains of the cations are long enough to show the tendency to segregate into apolar domains. In search of dynamic evidence for these nanostructures, different experimental techniques recently reported bimodal dynamic susceptibility spectra. In all cases, the faster process observed was ascribed to the structural α-relaxation and the slower one to the relaxation of long-lived aggregates. By contrast, we show by depolarized dynamic light scattering (DDLS) experiments on a systematic series of imidazolium-based ILs that the dynamics of the cation and anion are clearly separated for long alkyl chains. Therefore, the observation of a bimodal behavior is not related to any nanostructure but reflects the two-component nature of ILs. Thus, a consistent picture is obtained across different experimental methods, like dielectric and shear mechanical relaxation. Finally, the actual dynamic signature of nanostructures is identified for the first time as a weak feature in some of the DDLS spectra at even lower frequencies.
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Affiliation(s)
- Florian Pabst
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64289 Darmstadt , Germany
| | - Jan Gabriel
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64289 Darmstadt , Germany
| | - Thomas Blochowicz
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64289 Darmstadt , Germany
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20
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Bierwirth SP, Honorio G, Gainaru C, Böhmer R. Linear and nonlinear shear studies reveal supramolecular responses in supercooled monohydroxy alcohols with faint dielectric signatures. J Chem Phys 2019; 150:104501. [DOI: 10.1063/1.5086529] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- S. Peter Bierwirth
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Gabriel Honorio
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Catalin Gainaru
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Roland Böhmer
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
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21
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Substituted Azolium Disposition: Examining the Effects of Alkyl Placement on Thermal Properties. CRYSTALS 2019. [DOI: 10.3390/cryst9010034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We describe the thermal phase characteristics of a series of 4,5-bis(n-alkyl)azolium salts that were studied using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarized-light optical microscopy (POM), and synchrotron-based small- to wide-angle X-ray scattering (SWAXS) measurements. Key results were obtained for 1,3-dimethyl-4,5-bis(n-undecyl)imidazolium iodide (1-11), 1,3-dimethyl-4,5-bis(n-pentadecyl)- imidazolium iodide (1-15), and 1,2,3-trimethyl-4,5-bis(n-pentadecyl)imidazolium iodide (2), which were found to adopt enantiotropic smectic A mesophases. Liquid-crystalline mesophases were not observed for 1,3-dimethyl-4,5-bis(n-heptyl)imidazolium iodide (1-7), 3-methyl-4,5-bis(n-penta-decyl)thiazolium iodide (3), and 2-amino-4,5-bis(n-pentadecyl)imidazolium chloride (4). Installing substituents in the 4- and 5-positions of the imidazolium salts appears to increase melting points while lowering clearing points when compared to data reported for 1,3-disubstituted analogues.
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22
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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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23
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Cosby T, Vicars Z, Heres M, Tsunashima K, Sangoro J. Dynamic and structural evidence of mesoscopic aggregation in phosphonium ionic liquids. J Chem Phys 2018; 148:193815. [DOI: 10.1063/1.5009765] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- T. Cosby
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Z. Vicars
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M. Heres
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - K. Tsunashima
- Department of Applied Chemistry and Biochemistry, National Institute of Technology, Wakayama College, Wakayama 644-0023, Japan
| | - J. Sangoro
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
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24
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Zhang Q, Liu X, Yin L, Chen P, Wang Y, Yan T. Electrochemical impedance spectroscopy on the capacitance of ionic liquid–acetonitrile electrolytes. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.03.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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25
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Yamaguchi T, Saito M, Yoshida K, Yamaguchi T, Yoda Y, Seto M. Structural Relaxation and Viscoelasticity of a Higher Alcohol with Mesoscopic Structure. J Phys Chem Lett 2018; 9:298-301. [PMID: 29290123 DOI: 10.1021/acs.jpclett.7b02907] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This work studied the slow dynamics of liquids with mesoscopic structure and its relation to shear viscosity. Quasielastic scattering measurements were made on a liquid higher alcohol, 3,7-dimethyl-1-octanol, using γ-ray time-domain interferometry at a synchrotron radiation facility, SPring-8. The quasielastic scattering spectra were measured to determine the structural relaxation at two wavenumbers of the prepeak and the main peak of the static structure factor. It was found that relaxation at the prepeak is more than 10 times slower than that at the main peak. Compared with the viscoelastic spectrum, which exhibits bimodal relaxation, the relaxations at the prepeak and the main peak were shown to correspond to the slower and faster modes of the viscoelastic relaxation, respectively. This indicates that the dynamics of the mesoscopic structure represented as the prepeak contributes to the shear viscosity through the slowest mode of the viscoelastic relaxation.
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Affiliation(s)
- Tsuyoshi Yamaguchi
- Graduate School of Engineering, Nagoya University , Furo-cho B2-3 (611), Chikusa, Nagoya, Aichi 464-8603, Japan
| | - Makina Saito
- Research Reactor Institute, Kyoto University , Kumatori, Osaka 590-0494, 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
| | - Yoshitaka Yoda
- Research and Utilization Division, Japan Synchrotron Radiation Research Institute , Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Makoto Seto
- Research Reactor Institute, Kyoto University , Kumatori, Osaka 590-0494, Japan
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26
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Arrese-Igor S, Alegría A, Colmenero J. Multimodal character of shear viscosity response in hydrogen bonded liquids. Phys Chem Chem Phys 2018; 20:27758-27765. [DOI: 10.1039/c8cp04183k] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Non-simple viscosity response of 2E1H alcohol forming supramolecular aggregates.
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Affiliation(s)
- S. Arrese-Igor
- Centro de Física de Materiales (CSIC-UPV/EHU)
- Materials Physics Center (MPC)
- 20018 San Sebastián
- Spain
| | - A. Alegría
- Centro de Física de Materiales (CSIC-UPV/EHU)
- Materials Physics Center (MPC)
- 20018 San Sebastián
- Spain
- Departamento de Física de Materiales UPV/EHU
| | - J. Colmenero
- Centro de Física de Materiales (CSIC-UPV/EHU)
- Materials Physics Center (MPC)
- 20018 San Sebastián
- Spain
- Departamento de Física de Materiales UPV/EHU
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27
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Jensen MH, Gainaru C, Alba-Simionesco C, Hecksher T, Niss K. Slow rheological mode in glycerol and glycerol–water mixtures. Phys Chem Chem Phys 2018; 20:1716-1723. [DOI: 10.1039/c7cp06482a] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Glycerol–water mixtures were studied at molar concentrations ranging from xgly = 1 (neat glycerol) to xgly = 0.3 using shear mechanical spectroscopy.
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Affiliation(s)
- M. H. Jensen
- Glass & Time, IMFUFA, Department of Science and Environment, Roskilde University
- DK-4000 Roskilde
- Denmark
- Laboratoire Léon Brillouin, CNRS CEA-UMR 12, CEA Saclay
- 91191 Gif-sur-Yvette Cedex
| | - C. Gainaru
- Fakultät Physik, Technische Universität Dortmund
- 44221 Dortmund
- Germany
| | - C. Alba-Simionesco
- Laboratoire Léon Brillouin, CNRS CEA-UMR 12, CEA Saclay
- 91191 Gif-sur-Yvette Cedex
- France
| | - T. Hecksher
- Glass & Time, IMFUFA, Department of Science and Environment, Roskilde University
- DK-4000 Roskilde
- Denmark
| | - K. Niss
- Glass & Time, IMFUFA, Department of Science and Environment, Roskilde University
- DK-4000 Roskilde
- Denmark
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28
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Rams-Baron M, Jędrzejowska A, Dulski M, Wolnica K, Geirhos K, Lunkenheimer P, Paluch M. Unusual dielectric response of 4-methyl-1,3-dioxolane derivatives. Phys Chem Chem Phys 2018; 20:28211-28222. [DOI: 10.1039/c8cp05913f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In this paper, we applied broadband dielectric spectroscopy (BDS) to investigate the molecular dynamics of three 4-methyl-1,3-dioxolane derivatives (MD) whose chemical structures differ in the length of non-polar alkyl side chains.
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Affiliation(s)
- Marzena Rams-Baron
- Institute of Physics
- University of Silesia
- 41-500 Chorzow
- Poland
- Silesian Center for Education and Interdisciplinary Research
| | - Agnieszka Jędrzejowska
- Institute of Physics
- University of Silesia
- 41-500 Chorzow
- Poland
- Silesian Center for Education and Interdisciplinary Research
| | - Mateusz Dulski
- Silesian Center for Education and Interdisciplinary Research
- 41-500 Chorzow
- Poland
- Institute of Material Science
- 41-500 Chorzow
| | - Kamila Wolnica
- Institute of Physics
- University of Silesia
- 41-500 Chorzow
- Poland
- Silesian Center for Education and Interdisciplinary Research
| | - Korbinian Geirhos
- Experimental Physics V
- Center for Electronic Correlations and Magnetism
- University of Augsburg
- 86159 Augsburg
- Germany
| | - Peter Lunkenheimer
- Experimental Physics V
- Center for Electronic Correlations and Magnetism
- University of Augsburg
- 86159 Augsburg
- Germany
| | - Marian Paluch
- Institute of Physics
- University of Silesia
- 41-500 Chorzow
- Poland
- Silesian Center for Education and Interdisciplinary Research
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29
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Yamaguchi T. Coupling between the mesoscopic dynamics and shear stress of a room-temperature ionic liquid. Phys Chem Chem Phys 2018; 20:17809-17817. [DOI: 10.1039/c8cp02814a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Shear viscosity of an ionic liquid is governed by the dynamics of the charge-alternation mode irrespective of the presence of the domain structure.
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30
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Abstract
Structuring caused by the mixing of liquids or the addition of solutes to a solvent causes the viscosity to increase. The classical example is mayonnaise: a mixture of two low-viscosity liquids, water and oil, is structured through the addition of a surfactant creating a dispersed phase, causing the viscosity to increase a thousand-fold. The dramatic increase in viscosity in highly concentrated solutions is a long-standing unsolved problem in physical chemistry. Here we will show that this viscosity increase can be understood in terms of the solute-induced structuring of the first solvation shell, leading to a jamming transition at a critical concentration. As the jamming transition is approached, the viscosity naturally increases according to a Vogel-Fulcher-Tammann type expression. This result calls into question the validity of the Jones-Dole B-coefficient as an indicator of the structure making or breaking ability of solutes.
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Affiliation(s)
- Klaas Wynne
- School of Chemistry, University of Glasgow , Glasgow G12 8QQ, United Kingdom
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31
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Cosby T, Vicars Z, Mapesa EU, Tsunashima K, Sangoro J. Charge transport and dipolar relaxations in phosphonium-based ionic liquids. J Chem Phys 2017; 147:234504. [DOI: 10.1063/1.5011190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Tyler Cosby
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Zachariah Vicars
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Emmanuel Urandu Mapesa
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Katsuhiko Tsunashima
- Department of Applied Chemistry and Biochemistry, National Institute of Technology, Wakayama College, 77 Noshima, Nada-cho, Gobo, Wakayama 644-0023, Japan
| | - Joshua Sangoro
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
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