1
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Yao B, Alvarez VM, Paluch M, Fedor G, McLaughlin S, McGrogan A, Swadźba-Kwaśny M, Wojnarowska Z. Crystallization Kinetics of Phosphonium Ionic Liquids: Effect of Cation Alkyl Chain Length and Thermal History. J Phys Chem B 2024; 128:6610-6621. [PMID: 38924509 PMCID: PMC11247483 DOI: 10.1021/acs.jpcb.4c01720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Abstract
The effects of alkyl chain length on the crystallization kinetics and ion mobility of tetraalkylphosphonium, [P666,n][TFSI], (n = 2, 6, 8, and 12) ionic liquids were studied by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) over a wide temperature range. The liquid-glass transition temperature (Tg) and ion dynamics examined over a broad T range were almost insensitive to structural modifications of the phosphonium cation. In contrast, the crystallization kinetics were strongly affected by the length of the fourth alkyl chain. Furthermore, the thermal history of the sample (cold vs melt crystallization) significantly impacted the crystallization rate. It has been found that the nature of crystallization phenomena is the same across the homologous series, while the kinetic aspect differs. Finally, electric conductivity in supercooled liquid and crystalline solid phases was measured for all samples, revealing significant ionic conductivity, largely independent of the cation structure.
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Affiliation(s)
- B. Yao
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - V. Morales Alvarez
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - M. Paluch
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - G. Fedor
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - S. McLaughlin
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - A. McGrogan
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - M. Swadźba-Kwaśny
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - Z. Wojnarowska
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
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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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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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4
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Yao B, Paluch M, Dulski M, Quinn C, McLaughlin S, McGrogan A, Swadzba-Kwasny M, Wojnarowska Z. Tailoring Phosphonium Ionic Liquids for a Liquid-Liquid Phase Transition. J Phys Chem Lett 2023; 14:2958-2964. [PMID: 36939303 PMCID: PMC10068824 DOI: 10.1021/acs.jpclett.3c00099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
The existence of more than one liquid state in a single-component system remains the most intriguing physical phenomenon. Herein, we explore the effect of cation self-assembly on ion dynamics in the vicinity of liquid-liquid and liquid-glass transition of tetraalkyl phosphonium ([Pmmm,n]+, m = 4, 6; n = 2-14) ionic liquids. We found that nonpolar local domains formed by 14-carbon alkyl chains are crucial in obtaining two supercooled states of different dynamics within a single ionic liquid. Although the nano-ordering, confirmed by Raman spectroscopy, still occurs for shorter alkyl chains (m = 6, n < 14), it does not bring calorimetric evidence of LLT. Instead, it results in peculiar behavior of ion dynamics near the liquid-glass transition and 20-times smaller size of the dynamic heterogeneity compared to imidazolium ionic liquids. These results represent a crucial step toward understanding the nature of the LLT phenomenon and offer insight into the design of efficient electrolytes based on ionic liquids revealing self-assembly behavior.
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Affiliation(s)
- Beibei Yao
- Faculty
of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41−500 Chorzów, Poland
| | - Marian Paluch
- Faculty
of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41−500 Chorzów, Poland
| | - Mateusz Dulski
- Faculty
of Science and Technology, Institute of Materials Science, the University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41−500 Chorzów, Poland
| | - Courtney Quinn
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Road, BT9 5AG Belfast, Northern Ireland, U.K.
| | - Shannon McLaughlin
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Road, BT9 5AG Belfast, Northern Ireland, U.K.
| | - Anne McGrogan
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Road, BT9 5AG Belfast, Northern Ireland, U.K.
| | - Malgorzata Swadzba-Kwasny
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Road, BT9 5AG Belfast, Northern Ireland, U.K.
| | - Zaneta Wojnarowska
- Faculty
of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41−500 Chorzów, Poland
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5
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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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6
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Matsumoto M, Takeuchi K, Inoue Y, Tsunashima K, Yamada H. Molecular Insight into the Ionic Conduction of Quaternary Ammonium and Phosphonium Cation-Based Ionic Liquids Using Dielectric and Spectroscopy Analyses. J Phys Chem B 2022; 126:10490-10499. [PMID: 36417887 DOI: 10.1021/acs.jpcb.2c06110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We analyzed the primary properties of ionic liquids (ILs) comprising quaternary phosphonium cations and bis(trifluoromethylsulfonyl) amide anions and compared them with those of corresponding quaternary-ammonium-cation-based ILs. Broadband dielectric spectroscopy was used to confirm the coupling between the translational and orientational motions of ions, and our results demonstrated that the high ionic conductivity of the phosphonium-based ILs was attributed to their fast rotational dynamics. The differences between ILs with different cations were further evaluated using vibrational (Raman and terahertz) spectroscopy. The Raman spectroscopy data revealed that the cation structure affected the conformation and flexibility (conformational change) of the anion. Furthermore, terahertz spectroscopy allowed us to evaluate the relationship between ion transport and intermolecular interactions between the cation and anion of ILs.
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Affiliation(s)
- Mitsuhiro Matsumoto
- Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara639-1080, Japan
| | - Kazuki Takeuchi
- Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara639-1080, Japan
| | - Yohtaro Inoue
- Research Division of Polymer Functional Materials, Osaka Research Institute of Industrial Science and Technology, 2-7-1 Ayumino, Izumi, Osaka594-1157, Japan
| | - Katsuhiko Tsunashima
- Department of Applied Chemistry and Biochemistry, National Institute of Technology, Wakayama College, Gobo, Wakayama644-0023, Japan
| | - Hirohisa Yamada
- Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara639-1080, Japan
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7
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Dielectric Study of Tetraalkylammonium and Tetraalkylphosphonium Levulinate Ionic Liquids. Int J Mol Sci 2022; 23:ijms23105642. [PMID: 35628452 PMCID: PMC9145921 DOI: 10.3390/ijms23105642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/09/2022] [Accepted: 05/14/2022] [Indexed: 11/17/2022] Open
Abstract
Broadband dielectric spectroscopy in a broad temperature range was employed to study ionic conductivity and dynamics in tetraalkylammonium- and tetraalkylphosphonium-based ionic liquids (ILs) having levulinate as a common anion. Combining data for ionic conductivity with data obtained for viscosity in a Walden plot, we show that ionic conductivity is controlled by viscosity while a strong association of ions takes place. Higher values for ionic conductivities in a broad temperature range were found for the tetraalkylphosphonium-based IL compared to its ammonium homolog in accordance with its lower viscosity. Levulinate used in the present study as anion was found to interact and associate stronger with the cations forming ion-pairs or other complexes compared to the NTf2 anion studied in literature. In order to analyze dielectric data, different fitting approaches were employed. The original random barrier model cannot well describe the conductivity especially at the higher frequencies region. In electric modulus representation, two overlapping mechanisms contribute to the broad low frequencies peak. The slower process is related to the conduction mechanism and the faster to the main polarization process of the complex dielectric permittivity representation. The correlation of the characteristic time scales of the previous relaxation processes was discussed in terms of ionic interactions.
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8
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Rodriguez R, Baek D, Orme K, Case M, Fox R. Electrochemical, thermodynamic, and physical properties of tetradecyltrihexylphosphonium ([P6,6, 6,14]+) and methyl-propyl piperidinium containing ionic liquids and their propylene carbonate solutions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118607] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Wolf SE, Liu T, Govind S, Zhao H, Huang G, Zhang A, Wu Y, Chin J, Cheng K, Salami-Ranjbaran E, Gao F, Gao G, Jin Y, Pu Y, Toledo TG, Ablajan K, Walsh PJ, Fakhraai Z. Design of a homologous series of molecular glassformers. J Chem Phys 2021; 155:224503. [PMID: 34911316 DOI: 10.1063/5.0066410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We design and synthesize a set of homologous organic molecules by taking advantage of facile and tailorable Suzuki cross coupling reactions to produce triarylbenzene derivatives. By adjusting the number and the arrangement of conjugated rings, the identity of heteroatoms, lengths of fluorinated alkyl chains, and other interaction parameters, we create a library of glassformers with a wide range of properties. Measurements of the glass transition temperature (Tg) show a power-law relationship between Tg and molecular weight (MW), with of the molecules, with an exponent of 0.3 ± 0.1, for Tg values spanning a range of 300-450 K. The trends in indices of refraction and expansion coefficients indicate a general increase in the glass density with MW, consistent with the trends observed in Tg variations. A notable exception to these trends was observed with the addition of alkyl and fluorinated alkyl groups, which significantly reduced Tg and increased the dynamical fragility (which is otherwise insensitive to MW). This is an indication of reduced density and increased packing frustrations in these systems, which is also corroborated by the observations of the decreasing index of refraction with increasing length of these groups. These data were used to launch a new database for glassforming materials, glass.apps.sas.upenn.edu.
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Affiliation(s)
- Sarah E Wolf
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Tianyi Liu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Shivajee Govind
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Haoqiang Zhao
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Georgia Huang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Aixi Zhang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yu Wu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jocelyn Chin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Kevin Cheng
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | | - Feng Gao
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Gui Gao
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yi Jin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Youge Pu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Thiago Gomes Toledo
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Keyume Ablajan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Patrick J Walsh
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Zahra Fakhraai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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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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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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12
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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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13
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Perkin S, Kirchner B, Fayer MD. Preface: Special Topic on Chemical Physics of Ionic Liquids. J Chem Phys 2018; 148:193501. [DOI: 10.1063/1.5039492] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Susan Perkin
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Barbara Kirchner
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstr. 4, D-53115 Bonn, Germany
| | - Michael D. Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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14
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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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