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Grzybowski A, Koperwas K, Paluch M. Role of anisotropy in understanding the molecular grounds for density scaling in dynamics of glass-forming liquids. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:084501. [PMID: 38861964 DOI: 10.1088/1361-6633/ad569d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 06/11/2024] [Indexed: 06/13/2024]
Abstract
Molecular Dynamics (MD) simulations of glass-forming liquids play a pivotal role in uncovering the molecular nature of the liquid vitrification process. In particular, much focus was given to elucidating the interplay between the character of intermolecular potential and molecular dynamics behaviour. This has been tried to achieve by simulating the spherical particles interacting via isotropic potential. However, when simulation and experimental data are analysed in the same way by using the density scaling approaches, serious inconsistency is revealed between them. Similar scaling exponent values are determined by analysing the relaxation times and pVT data obtained from computer simulations. In contrast, these values differ significantly when the same analysis is carried out in the case of experimental data. As discussed thoroughly herein, the coherence between results of simulation and experiment can be achieved if anisotropy of intermolecular interactions is introduced to MD simulations. In practice, it has been realized in two different ways: (1) by using the anisotropic potential of the Gay-Berne type or (2) by replacing the spherical particles with quasi-real polyatomic anisotropic molecules interacting through isotropic Lenard-Jones potential. In particular, the last strategy has the potential to be used to explore the relationship between molecular architecture and molecular dynamics behaviour. Finally, we hope that the results presented in this review will also encourage others to explore how 'anisotropy' affects remaining aspects related to liquid-glass transition, like heterogeneity, glass transition temperature, glass forming ability, etc.
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Affiliation(s)
- A Grzybowski
- Institute of Physics, University of Silesia in Katowice, 41-500 Chorzów, Poland
| | - K Koperwas
- Institute of Physics, University of Silesia in Katowice, 41-500 Chorzów, Poland
| | - M Paluch
- Institute of Physics, University of Silesia in Katowice, 41-500 Chorzów, Poland
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2
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Liszka K, Grzybowski A, Grzybowska K, Koperwas K, Paluch M. Entropy Scaling of Molecular Dynamics in a Prototypical Anisotropic Model near the Glass Transition. J Phys Chem B 2023. [PMID: 37257018 DOI: 10.1021/acs.jpcb.3c02429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Dynamics and thermodynamics of molecular systems in the vicinity of the boundary between thermodynamically nonequilibrium glassy and metastable supercooled liquid states are still incompletely explored and their theoretical and simulation models are imperfect despite many previous efforts. Among them, the role of total system entropy, configurational entropy, and excess entropy in the temperature-pressure or temperature-density dependence of global molecular dynamics (MD) timescale relevant to the glass transition is an essential topic intensively studied for over half of a century. By exploiting a well-known simple ellipsoidal model recently successfully applied to simulate the supercooled liquid state and the glass transition, we gain a new insight into the different views on the relationship between entropy and relaxation dynamics of glass formers, showing the molecular grounds for the entropy scaling of global MD timescale. Our simulations in the anisotropic model of supercooled liquid, which involves only translational and rotational degrees of freedom, give evidence that the total system entropy is sufficient to scale global MD timescale. It complies with the scaling effect on relaxation dynamics exerted by the configurational entropy defined as the total entropy diminished by vibrational contributions, which was earlier discovered for measurement data collected near the glass transition. Moreover, we argue that such a scaling behavior is not possible to achieve by using the excess entropy that is in excess of the ideal gas entropy, which is contrary to the results earlier suggested within the framework of simple isotropic models of supercooled liquids. Thus, our findings also warn against an excessive reliance on isotropic models in theoretical interpretations of molecular phenomena, despite their simplicity and popularity, because they may reflect improperly various physicochemical properties of glass formers.
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Affiliation(s)
- Karol Liszka
- Institute of Physics, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1, 41-500 Chorzów, Poland
| | - Andrzej Grzybowski
- Institute of Physics, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1, 41-500 Chorzów, Poland
| | - Katarzyna Grzybowska
- Institute of Physics, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1, 41-500 Chorzów, Poland
| | - Kajetan Koperwas
- Institute of Physics, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1, 41-500 Chorzów, Poland
| | - Marian Paluch
- Institute of Physics, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1, 41-500 Chorzów, Poland
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3
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Cheng S, Musiał M, Wojnarowska Z, Ngai K, Jacquemin J, Paluch M. Universal scaling behavior of entropy and conductivity in ionic liquids. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Cheng S, Musiał M, Wojnarowska Z, Holt A, Roland CM, Drockenmuller E, Paluch M. Structurally Related Scaling Behavior in Ionic Systems. J Phys Chem B 2020; 124:1240-1244. [PMID: 31999929 PMCID: PMC7497657 DOI: 10.1021/acs.jpcb.9b10783] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/27/2020] [Indexed: 01/12/2023]
Abstract
We examine the density scaling properties of two ionic materials, a classic aprotic low molecular weight ionic liquid, 1-butyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide ([BMIm][BETI]), and a polymeric ionic liquid, poly(3-methyl-1,2,3-triazolium bis(trifluoromethylsulfonyl)imide) (TPIL). Density scaling is known to apply rigorously to simple liquids lacking specific intermolecular associations such as hydrogen bonds. Previous work has found that ionic liquids conform to density scaling over limited ranges of temperature and pressure. In this work, we find that the dc-conductivity of [BMIm][BETI] accurately scales for density changes of 17%; however, there is a departure from scaling for TPIL for even more modest variations of temperature and pressure. The entropy of both ionic samples conforms to density scaling only if the scaling exponent is allowed to vary linearly with the magnitude of the entropy.
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Affiliation(s)
- S. Cheng
- Institute
of Physics, University of Silesia in Katowice,
Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41−500 Chorzów, Poland
| | - M. Musiał
- Institute
of Physics, University of Silesia in Katowice,
Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41−500 Chorzów, Poland
| | - Z. Wojnarowska
- Institute
of Physics, University of Silesia in Katowice,
Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41−500 Chorzów, Poland
| | - A. Holt
- Naval
Research Laboratory, Chemistry Division, Washington, DC 20375-5342, United States
| | - C. M. Roland
- Naval
Research Laboratory, Chemistry Division, Washington, DC 20375-5342, United States
| | - E. Drockenmuller
- Univ
Lyon, Université Lyon 1, CNRS, Ingénierie des Matériaux Polymères, UMR
5223, F-69003, Lyon, France
| | - M. 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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Jedrzejowska A, Grzybowski A, Paluch M. In search of invariants for viscous liquids in the density scaling regime: investigations of dynamic and thermodynamic moduli. Phys Chem Chem Phys 2017; 19:18348-18355. [PMID: 28678273 DOI: 10.1039/c7cp01144j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In this paper, we report the nontrivial results of our investigations of dynamic and thermodynamic moduli in search of invariants for viscous liquids in the density scaling regime by using selected supercooled van der Waals liquids as representative materials. Previously, the dynamic modulus Mp-T (defined in the pressure-temperature representation by the ratio of isobaric activation energy and activation volume) as well as the ratio BT/Mp-T (where BT is the thermodynamic modulus defined as the inverse isothermal compressibility) have been suggested as some kinds of material constants. We have established that they are not valid in the explored wide range of temperatures T over a dozen decades of structural relaxation times τ. The temperature dependences of Mp-T and BT/Mp-T have been elucidated by comparison with the well-known measure of the relative contribution of temperature and density fluctuations to molecular dynamics near the glass transition, i.e., the ratio of isochoric and isobaric activation energies. Then, we have implemented an idea to transform the definition of the dynamic modulus Mp-T from the p-T representation to the V-T one. This idea relied on the disentanglement of combined temperature and density fluctuations involved in isobaric parameters and has resulted in finding an invariant for viscous liquids in the density scaling regime, which is the ratio of thermodynamic and dynamic moduli, BT/MV-T. In this way, we have constituted a characteristic of thermodynamics and molecular dynamics, which remains unchanged in the supercooled liquid state for a given material, the molecular dynamics of which obeys the power density scaling law.
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Affiliation(s)
- Agnieszka Jedrzejowska
- Institute of Physics, University of Silesia in Katowice, Uniwersytecka 4, 40-007 Katowice, Poland.
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Activation volume of selected liquid crystals in the density scaling regime. Sci Rep 2017; 7:42174. [PMID: 28181530 PMCID: PMC5299607 DOI: 10.1038/srep42174] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 01/06/2017] [Indexed: 01/20/2023] Open
Abstract
In this paper, we demonstrate and thoroughly analyze the activation volumetric properties of selected liquid crystals in the nematic and crystalline E phases in comparison with those reported for glass-forming liquids. In the analysis, we have employed and evaluated two entropic models (based on either total or configurational entropies) to describe the longitudinal relaxation times of the liquid crystals in the density scaling regime. In this study, we have also exploited two equations of state: volumetric and activation volumetric ones. As a result, we have established that the activation volumetric properties of the selected liquid crystals are quite opposite to such typical properties of glass-forming materials, i.e., the activation volume decreases and the isothermal bulk modulus increases when a liquid crystal is isothermally compressed. Using the model based on the configurational entropy, we suggest that the increasing pressure dependences of the activation volume in isothermal conditions and the negative curvature of the pressure dependences of isothermal longitudinal relaxation times can be related to the formation of antiparallel doublets in the examined liquid crystals. A similar pressure effect on relaxation dynamics may be also observed for other material groups in case of systems, the molecules of which form some supramolecular structures.
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Abstract
Although the freezing of liquids and melting of crystals are fundamental for many areas of the sciences, even simple properties like the temperature–pressure relation along the melting line cannot be predicted today. Here we present a theory in which properties of the coexisting crystal and liquid phases at a single thermodynamic state point provide the basis for calculating the pressure, density and entropy of fusion as functions of temperature along the melting line, as well as the variation along this line of the reduced crystalline vibrational mean-square displacement (the Lindemann ratio), and the liquid's diffusion constant and viscosity. The framework developed, which applies for the sizable class of systems characterized by hidden scale invariance, is validated by computer simulations of the standard 12-6 Lennard-Jones system. Melting is a classic first-order phase transition, but an accurate thermodynamic description is still lacking. Here, Pedersen et al. develop a theory, validated by simulations of the Lennard-Jones system, for the melting thermodynamics applicable to all systems characterized by hidden scale invariance.
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Costigliola L, Schrøder TB, Dyre JC. Communication: Studies of the Lennard-Jones fluid in 2, 3, and 4 dimensions highlight the need for a liquid-state 1/d expansion. J Chem Phys 2016; 144:231101. [DOI: 10.1063/1.4954239] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Lorenzo Costigliola
- Department of Science and Environment, “Glass and Time,” IMFUFA, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
| | - Thomas B. Schrøder
- Department of Science and Environment, “Glass and Time,” IMFUFA, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
| | - Jeppe C. Dyre
- Department of Science and Environment, “Glass and Time,” IMFUFA, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
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Grzybowska K, Capaccioli S, Paluch M. Recent developments in the experimental investigations of relaxations in pharmaceuticals by dielectric techniques at ambient and elevated pressure. Adv Drug Deliv Rev 2016; 100:158-82. [PMID: 26705851 DOI: 10.1016/j.addr.2015.12.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 12/05/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022]
Abstract
In recent years, there is a growing interest in improving the physicochemical stability of amorphous pharmaceutical solids due to their very promising applications to manufacture medicines characterized by a better water solubility, and consequently by a higher dissolution rate than those of their crystalline counterparts. In this review article, we show that the molecular mobility investigated both in the supercooled liquid and glassy states is the crucial factor required to understand molecular mechanisms that govern the physical stability of amorphous drugs. We demonstrate that pharmaceuticals can be thoroughly examined by means of the broadband dielectric spectroscopy, which is a very useful experimental technique to explore different relaxation processes and crystallization kinetics as well. Such studies conducted in the wide temperature and pressure ranges provide data needed in searching correlations between properties of molecular dynamics and crystallization process, which are aimed at developing effective and efficient methods for stabilizing amorphous drugs.
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Koperwas K, Grzybowski A, Tripathy SN, Masiewicz E, Paluch M. Thermodynamic consequences of the kinetic nature of the glass transition. Sci Rep 2015; 5:17782. [PMID: 26657017 PMCID: PMC4674716 DOI: 10.1038/srep17782] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/03/2015] [Indexed: 01/18/2023] Open
Abstract
In this paper, we consider the glass transition as a kinetic process and establish one universal equation for the pressure coefficient of the glass transition temperature, dTg/dp, which is a thermodynamic characteristic of this process. Our findings challenge the common previous expectations concerning key characteristics of the transformation from the liquid to the glassy state, because it suggests that without employing an additional condition, met in the glass transition, derivation of the two independent equations for dTg/dp is not possible. Hence, the relation among the thermodynamic coefficients, which could be equivalent to the well-known Prigogine-Defay ratio for the process under consideration, cannot be obtained. Besides, by comparing the predictions of our universal equation for dTg/dp and Ehrenfest equations, we find the aforementioned supplementary restriction, which must be met to use the Prigogine-Defay ratio for the glass transition.
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Affiliation(s)
- Kajetan Koperwas
- Institute of Physics, University of Silesia, Uniwersytecka
4, 40-007
Katowice, Poland
- Silesian Center for Education and Interdisciplinary
Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland
| | - Andrzej Grzybowski
- Institute of Physics, University of Silesia, Uniwersytecka
4, 40-007
Katowice, Poland
- Silesian Center for Education and Interdisciplinary
Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland
| | - Satya N. Tripathy
- Institute of Physics, University of Silesia, Uniwersytecka
4, 40-007
Katowice, Poland
- Silesian Center for Education and Interdisciplinary
Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland
| | - Elzbieta Masiewicz
- Institute of Physics, University of Silesia, Uniwersytecka
4, 40-007
Katowice, Poland
- Silesian Center for Education and Interdisciplinary
Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland
| | - Marian Paluch
- Institute of Physics, University of Silesia, Uniwersytecka
4, 40-007
Katowice, Poland
- Silesian Center for Education and Interdisciplinary
Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland
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11
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Masiewicz E, Grzybowski A, Grzybowska K, Pawlus S, Pionteck J, Paluch M. Adam-Gibbs model in the density scaling regime and its implications for the configurational entropy scaling. Sci Rep 2015; 5:13998. [PMID: 26365623 PMCID: PMC4568462 DOI: 10.1038/srep13998] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/31/2015] [Indexed: 11/15/2022] Open
Abstract
To solve a long-standing problem of condensed matter physics with determining a proper description of the thermodynamic evolution of the time scale of molecular dynamics near the glass transition, we have extended the well-known Adam-Gibbs model to describe the temperature-volume dependence of structural relaxation times, τα(T, V). We also employ the thermodynamic scaling idea reflected in the density scaling power law, τα = f(T−1V−γ), recently acknowledged as a valid unifying concept in the glass transition physics, to differentiate between physically relevant and irrelevant attempts at formulating the temperature-volume representations of the Adam-Gibbs model. As a consequence, we determine a straightforward relation between the structural relaxation time τα and the configurational entropy SC, giving evidence that also SC(T, V) = g(T−1V−γ) with the exponent γ that enables to scale τα(T, V). This important findings have meaningful implications for the connection between thermodynamics and molecular dynamics near the glass transition, because it implies that τα can be scaled with SC.
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Affiliation(s)
- Elżbieta Masiewicz
- Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.,Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Andrzej Grzybowski
- Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.,Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Katarzyna Grzybowska
- Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.,Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Sebastian Pawlus
- Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.,Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Jürgen Pionteck
- Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, D-01069 Dresden, Germany
| | - Marian Paluch
- Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.,Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
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