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Ediger MD, Gruebele M, Lubchenko V, Wolynes PG. Glass Dynamics Deep in the Energy Landscape. J Phys Chem B 2021; 125:9052-9068. [PMID: 34357766 DOI: 10.1021/acs.jpcb.1c01739] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
When a liquid is cooled, progress down the energy landscape is arrested near the glass transition temperature Tg. In principle, lower energy states can be accessed by waiting for further equilibration, but the rough energy landscape of glasses quickly leads to kinetics on geologically slow time scales below Tg. Over the past decade, progress has been made probing deeper into the energy landscape via several techniques. By looking at bulk and surface diffusion, using layered deposition that promotes equilibration, imaging glass surfaces with faster dynamics below Tg, and optically exciting glasses, experiments have moved into a regime of ultrastable, low energy glasses that was difficult to access in the past. At the same time, both simulations and energy landscape theory based on a random first order transition (RFOT) have tackled systems that include surfaces, optical excitation, and interfacial dynamics. Here we review some of the recent experimental work, and how energy landscape theory illuminates glassy dynamics well below the glass transition temperature by making direct connections between configurational entropy, energy landscape barriers, and the resulting dynamics.
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Affiliation(s)
- Mark D Ediger
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Martin Gruebele
- Department of Chemistry, Department of Physics, Center for Biophysics and Quantitative Biology, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, United States
| | - Vassiliy Lubchenko
- Departments of Chemistry and Physics, and the Center for Superconductivity, University of Houston, Houston, Texas 77204, United States
| | - Peter G Wolynes
- Departments of Chemistry, Physics and Astronomy, Biosciences, Materials Science and Nanoengineering, and the Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
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2
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Drzewicz A, Jasiurkowska-Delaporte M, Juszyńska-Gałązka E, Zając W, Kula P. On the relaxation dynamics of a double glass-forming antiferroelectric liquid crystal. Phys Chem Chem Phys 2021; 23:8673-8688. [PMID: 33876028 DOI: 10.1039/d0cp06203k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The relaxation dynamics in the thermodynamic states of the glass-forming antiferroelectric liquid crystal (S)-4'-(1-methyloctyloxycarbonyl) biphenyl-4-yl 4-[7-(2,2,3,3,4,4,4-heptafluorobutoxy) heptyl-1-oxy]-benzoate (3F7HPhH7) was studied by broadband dielectric spectroscopy (BDS). Two glass transitions were found at Tg,1 = 259 K and Tg,2 = 239 K, which were associated with the freezing of anti-phase motions and reorientation around the long molecular axis in the antiferroelectric SmCA* phase, respectively. The low temperature α2-relaxation process shows a Vogel-Fulcher-Tammann (VFT)-type temperature dependence of its structural relaxation time τ(T). The two secondary β- and γ-relaxation modes ascribed to the intramolecular motions observed in the glassy state show Arrhenius behaviour of τ(T). Analysing the band shifts and the oscillator strengths of specific IR absorption bands and their temperature dependencies enables comparing them with the dielectrically determined relaxation dynamics. The kinetics of the isothermal cold crystallization in the temperature range between Tg,1 and Tg,2 was studied in detail using the Avrami and Avrami-Avramow models. This process depends primarily on the diffusion rate and the activation energy is equal to 132 kJ mol-1. The obtained values of the Avrami exponent nA suggest that the crystal growth is three-dimensional.
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Affiliation(s)
- Anna Drzewicz
- Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland.
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3
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Zhang G, Rocha S, Lu G, Yuan H, Uji-i H, Floudas GA, Müllen K, Xiao L, Hofkens J, Debroye E. Spatially and Temporally Resolved Heterogeneities in a Miscible Polymer Blend. ACS OMEGA 2020; 5:23931-23939. [PMID: 32984713 PMCID: PMC7513360 DOI: 10.1021/acsomega.0c03173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
Mapping the spatial and temporal heterogeneities in miscible polymer blends is critical for understanding and further improving their material properties. However, a complete picture on the heterogeneous dynamics is often obscured in ensemble measurements. Herein, the spatial and temporal heterogeneities in fully miscible polystyrene/oligostyrene blend films are investigated by monitoring the rotational diffusion of embedded individual probe molecules using defocused wide-field fluorescence microscopy. In the same blend film, three significantly different types of dynamical behaviors (referred to as modes) of the probe molecules can be observed at the same time, namely, immobile, continuously rotating, and intermittently rotating probe molecules. This reveals a prominent spatial heterogeneity in local dynamics at the nanometer scale. In addition to that, temporal heterogeneity is uncovered by the nonexponential characteristic of the rotational autocorrelation functions of single-molecule probes. Moreover, the occurrence probabilities of these different modes strongly depend on the polystyrene: oligostyrene ratios in the blend films. Remarkably, some probe molecules switch between the continuous and intermittent rotational modes at elevated temperature, indicating a possible alteration in local dynamics that is triggered by the dynamic heterogeneity in the blends. Although some of these findings can be discussed by the self-concentration model and the results provided by ensemble averaging techniques (e.g., dielectric spectroscopy), there are implications that go beyond current models of blend dynamics.
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Affiliation(s)
- Guofeng Zhang
- State
Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute
of Laser Spectroscopy, Collaborative Innovation Center of Extreme
Optics, Shanxi University, Taiyuan, 030006, China
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
| | - Susana Rocha
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
| | - Gang Lu
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
- Institute
of Advanced Materials & Key Laboratory of Flexible Electronics, Nanjing Tech University, Nanjing 211816, China
| | - Haifeng Yuan
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
| | - Hiroshi Uji-i
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
- Research
Institute for Electronic Science (RIES), Hokkaido University, N20W10, Sapporo City 001-0020, Japan
| | - George A. Floudas
- Department
of Physics, University of Ioannina, GR-45110 Ioannina, Greece
- Max
Plank Institute for Polymer Research, Mainz D-55128, Germany
| | - Klaus Müllen
- Max
Plank Institute for Polymer Research, Mainz D-55128, Germany
| | - Liantuan Xiao
- State
Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute
of Laser Spectroscopy, Collaborative Innovation Center of Extreme
Optics, Shanxi University, Taiyuan, 030006, China
| | - Johan Hofkens
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
- Max
Plank Institute for Polymer Research, Mainz D-55128, Germany
| | - Elke Debroye
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
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Jasiurkowska-Delaporte M, Rozwadowski T, Dmochowska E, Juszyńska-Gałązka E, Kula P, Massalska-Arodź M. Interplay between Crystallization and Glass Transition in Nematic Liquid Crystal 2,7-Bis(4-pentylphenyl)-9,9-diethyl-9 H-fluorene. J Phys Chem B 2018; 122:10627-10636. [PMID: 30376333 DOI: 10.1021/acs.jpcb.8b08138] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This article presents the crystallization behavior and molecular dynamics of the supercooled nematic state of the newly synthesized liquid crystal 2,7-bis(4-pentylphenyl)-9,9-diethyl-9 H-fluorene (5P-EtFLEt-P5) studied by means of broadband dielectric spectroscopy (BDS). 5P-EtFLEt-P5 is a fragile glass-forming system with a high fragility parameter ( mf ≈ 121). The study compares the isothermal melt- and cold-crystallization processes at several selected temperatures Tc in the vicinity of the glass-transition temperature Tg (1.07 Tg ≤ T ≤ 1.17 Tg). Our findings reveal that at low temperatures, the crystallization of the Cr1 phase from the nematic melt state occurs more quickly than the cold crystallization. The dimensionality of the growing crystallites ( n) was found to be slightly higher for the cold- than for the melt-crystallization process, varying from n ∼ 5 to n ∼ 3 with increasing temperature. Our experimental results are discussed in terms of dynamic and thermodynamic properties of the material. The study also uses polarized optical microscopy to investigate the isothermal secondary cold crystallization (the formation of Cr2 from Cr1 upon heating), which is inaccessible by BDS measurements because of its very fast crystallization rates.
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Affiliation(s)
| | - Tomasz Rozwadowski
- The Henryk Niewodniczański Institute of Nuclear Physics , Polish Academy of Sciences , Radzikowskiego 152 , 31-342 Kraków , Poland
| | - Ewelina Dmochowska
- Institute of Chemistry , Military University of Technology , 01-476 Warsaw , Poland
| | - Ewa Juszyńska-Gałązka
- The Henryk Niewodniczański Institute of Nuclear Physics , Polish Academy of Sciences , Radzikowskiego 152 , 31-342 Kraków , Poland
| | - Przemysław Kula
- Institute of Chemistry , Military University of Technology , 01-476 Warsaw , Poland
| | - Maria Massalska-Arodź
- The Henryk Niewodniczański Institute of Nuclear Physics , Polish Academy of Sciences , Radzikowskiego 152 , 31-342 Kraków , Poland
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Thermal Study of Polyols for the Technological Application as Plasticizers in Food Industry. Polymers (Basel) 2018; 10:polym10050467. [PMID: 30966501 PMCID: PMC6415443 DOI: 10.3390/polym10050467] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 12/05/2022] Open
Abstract
In this work is presented the complete thermal analysis of polyols by direct methods such as simultaneous thermogravimetric and differential thermal analyzer (TGA-DTA), differential scanning calorimetry (DSC), modulated DSC (MDSC), and supercooling MDSC. The different thermal events in the temperature range of 113–553 K were identified for glycerol (GL), ethylene glycol (EG), and propylene glycol (PG). Boiling temperature (TB) decreased as GL > EG > PG, but increased with the heating rate. GL showed a complex thermal event at 191–199 K, identified as the glass transition temperature (Tg) and devitrification temperature (Tdv), and a liquid–liquid transition (TL-L) at 215–221 K was identified as the supercooling temperature. EG showed several thermal events such as Tg and Tdv at 154 K, crystallization temperature (Tc) at 175 K, and melting temperature (Tm) at 255 K. PG also showed a complex thermal event (Tg and Tdv) at 167 K, a second devitrification at 193 K, and TL-L at 245 K. For PG, crystallization was not observed, indicating that, during the cooling, the liquid remained as an amorphous solid.
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7
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Jensen MH, Alba-Simionesco C, Niss K, Hecksher T. A systematic study of the isothermal crystallization of the mono-alcohol n-butanol monitored by dielectric spectroscopy. J Chem Phys 2016; 143:134501. [PMID: 26450317 DOI: 10.1063/1.4931807] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Isothermal crystallization of the mono-hydroxyl alcohol n-butanol was studied with dielectric spectroscopy in real time. The crystallization was carried out using two different sample cells at 15 temperatures between 120 K and 134 K. Crystallization is characterized by a decrease of the dielectric intensity. In addition, a shift in relaxation times to shorter times was observed during the crystallization process for all studied temperatures. The two different sample environments induced quite different crystallization behaviors, consistent and reproducible over all studied temperatures. An explanation for the difference was proposed on the background of an Avrami analysis and a Maxwell-Wagner analysis. Both types of analysis suggest that the morphology of the crystal growth changes from a higher dimension to a lower at a point during the crystallization. More generally, we conclude that a microscopic interpretation of crystallization measurements requires multiple probes, sample cells, and protocols.
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Affiliation(s)
- M H Jensen
- Department of Sciences, DNRF Centre Glass and Time, IMFUFA, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
| | - C Alba-Simionesco
- Laboratoire Léon Brillouin, CNRS CEA -UMR 12, DSM IRAMIS LLB CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - K Niss
- Department of Sciences, DNRF Centre Glass and Time, IMFUFA, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
| | - T Hecksher
- Department of Sciences, DNRF Centre Glass and Time, IMFUFA, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
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Busselez R, Pezeril T, Gusev VE. Structural heterogeneities at the origin of acoustic and transport anomalies in glycerol glass-former. J Chem Phys 2015; 140:234505. [PMID: 24952550 DOI: 10.1063/1.4883504] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
By means of large scale molecular dynamics simulations, we explore mesoscopic properties of prototypical glycerol glass-former above and below the glass transition. The model used, in excellent agreement with various experimental techniques, permits to carefully study the structure and the vibrational dynamics. We find that a medium range order is present in glycerol glass-former and arises from hydrogen bond network extension. The characteristic size of the structural heterogeneities is related to the anomalous properties of acoustic vibrations (Rayleigh scattering, "mode softening," and Boson Peak) in the glassy state. Finally the characteristic size of these heterogeneities, nearly constant in temperature, is also connected to the cross-over between structural relaxation and diffusion in liquid glycerol.
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Affiliation(s)
- Rémi Busselez
- Institut des Molécules et Matériaux du Mans UMR-CNRS 6283, Université du Maine, Le Mans, France
| | - Thomas Pezeril
- Institut des Molécules et Matériaux du Mans UMR-CNRS 6283, Université du Maine, Le Mans, France
| | - Vitalyi E Gusev
- Laboratoire d'Acoustique de l'Université du Maine, UMR-CNRS 6613 Université du Maine, Le Mans, France
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Sanz A, Nogales A, Puente-Orench I, Jiménez-Ruiz M, Ezquerra TA. Changes in mobility of plastic crystal ethanol during its transformation into the monoclinic crystal state. J Chem Phys 2014; 140:054510. [PMID: 24511955 DOI: 10.1063/1.4863694] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Transformation of deuterated ethanol from the plastic crystal phase into the monoclinic one is investigated by means of a singular setup combining simultaneously dielectric spectroscopy with neutron diffraction. We postulate that a dynamic transition from plastic crystal to supercooled liquid-like configuration through a deep reorganization of the hydrogen-bonding network must take place as a previous step of the crystallization process. Once these precursor regions are formed, subsequent crystalline nucleation and growth develop with time.
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Affiliation(s)
- Alejandro Sanz
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid, Spain
| | - Aurora Nogales
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid, Spain
| | | | | | - Tiberio A Ezquerra
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid, Spain
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Kaufman LJ. Heterogeneity in Single-Molecule Observables in the Study of Supercooled Liquids. Annu Rev Phys Chem 2013; 64:177-200. [DOI: 10.1146/annurev-physchem-040412-110033] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bulk approaches to studying heterogeneous systems obscure important details, as they report average behavior rather than the distribution of behaviors in such environments. Small-molecule and polymeric supercooled liquids, which display heterogeneity in their dynamics without an underlying structural heterogeneity that sets those dynamics, are important constituents of this category of condensed matter systems. A variety of approaches have been devised to unravel ensemble averaging in supercooled liquids. This review focuses on the ultimate subensemble approach, single-molecule measurements, as they have been applied to the study of supercooled liquids. We detail how three key experimental observables (single-molecule probe rotation, translation, and fluorescence lifetime) have been employed to provide detail on dynamic heterogeneity in supercooled liquids. Special attention is given to the potential for, but also the challenges in, discriminating spatial and temporal heterogeneity and detailing the length scales and timescales of heterogeneity in these systems.
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Affiliation(s)
- Laura J. Kaufman
- Department of Chemistry, Columbia University, New York, NY 10027
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11
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Orrit M. Ein molekularer Blick auf die Heterogenität in Gläsern. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201205231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Yuan H, Khatua S, Zijlstra P, Orrit M. Individual gold nanorods report on dynamical heterogeneity in supercooled glycerol. Faraday Discuss 2013; 167:515-27. [DOI: 10.1039/c3fd00091e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Orrit M. Towards a Molecular View of Glass Heterogeneity. Angew Chem Int Ed Engl 2012; 52:163-6. [DOI: 10.1002/anie.201205231] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 08/20/2012] [Indexed: 11/08/2022]
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