1
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Luo J, Wang X, Tong B, Li Z, Rocchi LA, Di Lisio V, Cangialosi D, Zuo B. Length Scale of Molecular Motions Governing Glass Equilibration in Hyperquenched and Slow-Cooled Polystyrene. J Phys Chem Lett 2024; 15:357-363. [PMID: 38175163 DOI: 10.1021/acs.jpclett.3c03263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Polymer glasses attain thermodynamic equilibrium owing to structural relaxation at various length scales. Herein, calorimetry experiments were conducted to trace the macroscopic relaxation of slow-cooled (SC) and hyperquenched (HQ) polystyrene (PS) glasses and based on detailed comparisons with molecular dynamics probed by dye reorientation, we discussed the possible molecular process governing the equilibration of PS glasses near the glass transition temperatures (Tg). Both SC and HQ glasses equilibrate owing to the cooperative segment motion above a characteristic temperature (Tc) slightly lower than the Tg. In contrast, below the Tc, the localized backbone motion with an apparent activation energy of 290 ± 20 kJ/mol, involving approximately six repeating units, assists equilibrium recovery of PS glasses on the experimentally accessible time scales. The results possibly indicate the presence of an alternative mechanism other than the α-cooperative process controlling physical aging of materials in their deep glassy states.
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Affiliation(s)
- Jintian Luo
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xiang Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Ben Tong
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Zhiqiang Li
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Lorenzo Augusto Rocchi
- Department of Chemistry, University of Rome "La Sapienza", P.le A. Moro 5, 00185 Rome, Italy
| | - Valerio Di Lisio
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastian, Spain
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastian, Spain
- Centro de Física de Materiales, Paseo Manuel de Lardizabal 5, 20018 San Sebastian, Spain
| | - Biao Zuo
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
- Zhejiang Provincial Innovation Center of Advanced Textile Technology, Shaoxing 312000, China
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2
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Di Lisio V, Gallino I, Riegler SS, Frey M, Neuber N, Kumar G, Schroers J, Busch R, Cangialosi D. Size-dependent vitrification in metallic glasses. Nat Commun 2023; 14:4698. [PMID: 37542023 PMCID: PMC10403508 DOI: 10.1038/s41467-023-40417-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 07/26/2023] [Indexed: 08/06/2023] Open
Abstract
Reducing the sample size can profoundly impact properties of bulk metallic glasses. Here, we systematically reduce the length scale of Au and Pt-based metallic glasses and study their vitrification behavior and atomic mobility. For this purpose, we exploit fast scanning calorimetry (FSC) allowing to study glassy dynamics in an exceptionally wide range of cooling rates and frequencies. We show that the main α relaxation process remains size independent and bulk-like. In contrast, we observe pronounced size dependent vitrification kinetics in micrometer-sized glasses, which is more evident for the smallest samples and at low cooling rates, resulting in more than 40 K decrease in fictive temperature, Tf, with respect to the bulk. We discuss the deep implications on how this outcome can be used to convey glasses to low energy states.
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Affiliation(s)
- Valerio Di Lisio
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018, San Sebastián, Spain
| | - Isabella Gallino
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany.
| | | | - Maximilian Frey
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany
| | - Nico Neuber
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany
| | - Golden Kumar
- Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX, USA
| | - Jan Schroers
- Yale University, Mechanical Engineering and Materials Science, New Haven, CT, USA
| | - Ralf Busch
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018, San Sebastián, Spain.
- Centro de Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018, San Sebastián, Spain.
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3
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Herrero C, Scalliet C, Ediger MD, Berthier L. Two-step devitrification of ultrastable glasses. Proc Natl Acad Sci U S A 2023; 120:e2220824120. [PMID: 37040403 PMCID: PMC10120036 DOI: 10.1073/pnas.2220824120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/11/2023] [Indexed: 04/12/2023] Open
Abstract
The discovery of ultrastable glasses raises novel challenges about glassy systems. Recent experiments studied the macroscopic devitrification of ultrastable glasses into liquids upon heating but lacked microscopic resolution. We use molecular dynamics simulations to analyze the kinetics of this transformation. In the most stable systems, devitrification occurs after a very large time, but the liquid emerges in two steps. At short times, we observe the rare nucleation and slow growth of isolated droplets containing a liquid maintained under pressure by the rigidity of the surrounding glass. At large times, pressure is released after the droplets coalesce into large domains, which accelerates devitrification. This two-step process produces pronounced deviations from the classical Avrami kinetics and explains the emergence of a giant lengthscale characterizing the devitrification of bulk ultrastable glasses. Our study elucidates the nonequilibrium kinetics of glasses following a large temperature jump, which differs from both equilibrium relaxation and aging dynamics, and will guide future experimental studies.
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Affiliation(s)
- Cecilia Herrero
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier34095, France
| | - Camille Scalliet
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, CambridgeCB3 0WA, United Kingdom
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin–Madison, Madison, WI53706
| | - Ludovic Berthier
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier34095, France
- Yusuf Hamied Department of Chemistry, University of Cambridge, CambridgeCB2 1EW, United Kingdom
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4
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Laudicina CCL, Luo C, Miyazaki K, Janssen LMC. Dynamical susceptibilities near ideal glass transitions. Phys Rev E 2022; 106:064136. [PMID: 36671198 DOI: 10.1103/physreve.106.064136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Building on the recently derived inhomogeneous mode-coupling theory, we extend the generalized mode-coupling theory of supercooled liquids to inhomogeneous environments. This provides a first-principles-based, systematic, and rigorous way of deriving high-point dynamical susceptibilities from variations of the many-body dynamic structure factors with respect to their conjugate field. This framework allows for a fully microscopic possibility to probe for collective relaxation mechanisms in supercooled liquids near the mode-coupling glass transition. The behavior of these dynamical susceptibilities is then studied in the context of simplified self-consistent relaxation models.
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Affiliation(s)
- Corentin C L Laudicina
- Soft Matter & Biological Physics, Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Chengjie Luo
- Soft Matter & Biological Physics, Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | | | - Liesbeth M C Janssen
- Soft Matter & Biological Physics, Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
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5
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Structural Anomaly in Glasses: Molecular Dynamics Study of Organic Radical in Dibutylphthalate at Different Temperatures. Int J Mol Sci 2022; 23:ijms232314859. [PMID: 36499187 PMCID: PMC9735606 DOI: 10.3390/ijms232314859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022] Open
Abstract
Understanding the heterogeneous nano/microscopic structures of various organic glasses is fundamental and necessary for many applications. Recently, unusual structural phenomena have been observed experimentally in various organic glasses near their glass transition temperatures (Tg), including dibutyl phthalate (DBP). In particular, the librational motion of radical probe in the glass is progressively suppressed upon temperature increase. In this work, we report in-depth molecular dynamics studies of structural anomalies in DBP glass, that revealed insights into the general mechanism of these phenomena. In particular, we have evidenced that the two types of solvation within alkyl chains coexist, allowing only small-angle wobbling of the solute molecule (TEMPO radical), and another favouring large-angle rotations. The former solvation assumes constrained location of the solute near carboxyl groups of DBP, while the latter is coupled to the concerted movement of butyl chains. Remarkably, excellent qualitative and quantitative agreement with previous experimental results were obtained. As such, we are certain that the above-mentioned dynamic phenomena explain the intriguing structural anomalies observed in DBP and some other glasses in the vicinity of Tg.
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6
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Seo Y, Zuo B, Cangialosi D, Priestley RD. Physical aging of hydroxypropyl methylcellulose acetate succinate via enthalpy recovery. SOFT MATTER 2022; 18:8331-8341. [PMID: 36300535 DOI: 10.1039/d2sm01189a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Amorphous solid dispersions (ASDs) utilize the kinetic stability of the amorphous state to stabilize drug molecules within a glassy polymer matrix. Therefore, understanding the glassy-state stability of the polymer excipient is critical to ASD design and performance. Here, we investigated the physical aging of hydroxypropyl methylcellulose acetate succinate (HPMCAS), a commonly used polymer in ASD formulations. We found that HPMCAS exhibited conventional physical aging behavior when annealed near the glass transition temperature (Tg). In this scenario, structural recovery was facilitated by α-relaxation dynamics. However, when annealed well below Tg, a sub-α-relaxation process facilitated low-temperature physical aging in HPMCAS. Nevertheless, the physical aging rate exhibited no significant change up to 40 K below Tg, below which it exhibited a near monotonic decrease with decreasing temperature. Finally, infrared spectroscopy was employed to assess any effect of physical aging on the chemical structure of HPMCAS, which is known to be susceptible to degradation at temperatures 30 K above its Tg. Our results provide critical insights necessary to understand better the link between the stability of ASDs and physical aging of the glassy polymer matrix.
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Affiliation(s)
- Yejoon Seo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08540, USA
| | - Biao Zuo
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Daniele Cangialosi
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal 4, 20018, San Sebastián, Spain
- Centro de Fisica de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizábal 5, 20018, San Sebastián, Spain
| | - Rodney D Priestley
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08540, USA
- Princeton Institute for the Science and Technology of Materials, Princeton University, 41 Olden St, A215 Chemical and Biological Engineering, Princeton, New Jersey 08540, USA.
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7
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Cangialosi D, Alegría A, Colmenero J. Comment on “Anomalous structural recovery in the near glass transition range in a polymer glass: Data revisited in light of temperature variability in vacuum oven‐based experiments”. POLYM ENG SCI 2022. [DOI: 10.1002/pen.26054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Daniele Cangialosi
- Centro de Fisica de Materiales (CSIC‐UPV/EHU) Sebastián Spain
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología (UPV/EHU) San Sebastián Spain
| | - Angel Alegría
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología (UPV/EHU) San Sebastián Spain
- Donostia International Physics Center San Sebastián Spain
| | - Juan Colmenero
- Centro de Fisica de Materiales (CSIC‐UPV/EHU) Sebastián Spain
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología (UPV/EHU) San Sebastián Spain
- Donostia International Physics Center San Sebastián Spain
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8
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Ivanov MY, Surovtsev NV, Fedin MV. Ionic liquid glasses: properties and applications. RUSSIAN CHEMICAL REVIEWS 2022. [DOI: 10.1070/rcr5031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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9
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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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10
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Kaur H, Berg MA. Jump-precursor state emerges below the crossover temperature in supercooled o-terphenyl. Phys Rev E 2021; 103:L050601. [PMID: 34134282 DOI: 10.1103/physreve.103.l050601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
In a supercooled liquid, the crossover temperature T_{c} separates a high-temperature region of diffusive dynamics from a low-temperature region of activated dynamics. A molecular-dynamics simulation of all-atom, flexible o-terphenyl [Eastwood et al., J. Phys. Chem. B 117, 12898 (2013)10.1021/jp402102w] is analyzed with advanced statistical methods to reveal the molecular features associated with this crossover. The simulations extend to an α-relaxation time of 14 μs (272.5 K), two orders of magnitude slower than at T_{c} (290 K). At T_{c} and below, a distinct state emerges that immediately precedes an orientational jump. Compared to the initial, tightly caged state, this jump-precursor state has a looser cage, with solid-angular excursions of 0.054-0.0125 × 4π sr. At T_{c} (290 K), rate heterogeneity is already the dominant cause of stretched relaxation. Exchange within the distribution of rates is faster than α relaxation at T_{c}, but becomes equal to it at the lowest temperature simulated (272.5 K). The results trend toward a recent experimental observation near the glass transition (243 K) [Kaur et al., Phys. Rev. E 98, 040603(R) (2018)10.1103/PhysRevE.98.040603], which saw exchange substantially slower than α relaxation. Overall, the dynamic crossover comprises multiple phenomena: the development of heterogeneity, an increasing jump size, an emerging jump-precursor state, and a lengthening exchange time. The crossover is neither sharp, nor a simple superposition of the high- and low-temperature regimes; it is a broad region that contains unique and complex phenomena.
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Affiliation(s)
- Harveen Kaur
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
| | - Mark A Berg
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
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11
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Monnier X, Marina S, Lopez de Pariza X, Sardón H, Martin J, Cangialosi D. Physical Aging Behavior of a Glassy Polyether. Polymers (Basel) 2021; 13:954. [PMID: 33804594 PMCID: PMC8003685 DOI: 10.3390/polym13060954] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 11/16/2022] Open
Abstract
The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.
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Affiliation(s)
- Xavier Monnier
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain;
| | - Sara Marina
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Xabier Lopez de Pariza
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Haritz Sardón
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Jaime Martin
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
- Centro de Investigacións Tecnolóxicas, Universidade da Coruña, Campus de Esteiro s/n, 15403 Ferrol, Spain
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain;
- Centro de Fisica de Materiales (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5, 20018 Sebastián, Spain
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12
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Monnier X, Colmenero J, Wolf M, Cangialosi D. Reaching the Ideal Glass in Polymer Spheres: Thermodynamics and Vibrational Density of States. PHYSICAL REVIEW LETTERS 2021; 126:118004. [PMID: 33798388 DOI: 10.1103/physrevlett.126.118004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/04/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
The existence of an ideal glass and the resolution to the Kauzmann paradox is a long-standing open question in materials science. To address this problem, we exploit the ability of glasses with large interfacial area to access low energy states. We submit aggregates of spheres of a polymeric glass former to aging well below their glass transition temperature, T_{g}; and characterize their thermodynamic state by calorimetry, and the vibrational density of state (VDOS) by inelastic neutron scattering (INS). We show that, when aged at appropriate temperatures, glassy spheres attain a thermodynamic state corresponding to an ideal glass in time scales of about one day. In this state, the boson peak, underlying the deviation from the Debye level of the VDOS, is essentially suppressed. Our results are discussed in the framework of the link between the macroscopic thermodynamic state of glasses and their vibrational properties.
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Affiliation(s)
- Xavier Monnier
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - Juan Colmenero
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- Departamento de Fisica de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
- Centro de Fisica de Materiales (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - Marcel Wolf
- Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstrasse 1 85747, Garching, Germany
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- Centro de Fisica de Materiales (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
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13
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Lubchenko V, Wolynes PG. Photon Activation of Glassy Dynamics: A Mechanism for Photoinduced Fluidization, Aging, and Information Storage in Amorphous Materials. J Phys Chem B 2020; 124:8434-8453. [DOI: 10.1021/acs.jpcb.0c06515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vassiliy Lubchenko
- Departments of Chemistry and Physics, and Texas Center for Superconductivity, University of Houston, Houston 77204-5003, Texas, 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 77005, Texas, United States
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14
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Lulli M, Lee CS, Deng HY, Yip CT, Lam CH. Spatial Heterogeneities in Structural Temperature Cause Kovacs' Expansion Gap Paradox in Aging of Glasses. PHYSICAL REVIEW LETTERS 2020; 124:095501. [PMID: 32202859 DOI: 10.1103/physrevlett.124.095501] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
Volume and enthalpy relaxation of glasses after a sudden temperature change has been extensively studied since Kovacs' seminal work. One observes an asymmetric approach to equilibrium upon cooling versus heating and, more counterintuitively, the expansion gap paradox, i.e., a dependence on the initial temperature of the effective relaxation time even close to equilibrium when heating. Here, we show that a distinguishable-particle lattice model can capture both the asymmetry and the paradox. We quantitatively characterize the energetic states of the particle configurations using a physical realization of the fictive temperature called the structural temperature, which, in the heating case, displays a strong spatial heterogeneity. The system relaxes by nucleation and expansion of warmer mobile domains having attained the final temperature, against cooler immobile domains maintained at the initial temperature. A small population of these cooler regions persists close to equilibrium, thus explaining the paradox.
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Affiliation(s)
- Matteo Lulli
- Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong, China
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Chun-Shing Lee
- Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong, China
| | - Hai-Yao Deng
- School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom
- School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, United Kingdom
| | - Cho-Tung Yip
- School of Science, Harbin Institute of Technology, Shenzhen Graduate School, Shenzhen, Guangdong 518055, China
| | - Chi-Hang Lam
- Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong, China
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15
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Vila-Costa A, Ràfols-Ribé J, González-Silveira M, Lopeandia AF, Abad-Muñoz L, Rodríguez-Viejo J. Nucleation and Growth of the Supercooled Liquid Phase Control Glass Transition in Bulk Ultrastable Glasses. PHYSICAL REVIEW LETTERS 2020; 124:076002. [PMID: 32142312 DOI: 10.1103/physrevlett.124.076002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
We report the anomalous bulk transformation of vapor deposited stable glasses into the liquid state. The transformation proceeds through two competing parallel processes: partial rejuvenation of the stable glass and nucleation and growth of liquid patches within the glass. The kinetics of the transformation extracted from heat capacity curves after isothermal runs is dominated by the heterogeneous nucleation and growth process that initiates at preexisting seeds and propagates radially at a velocity proportional to the alpha relaxation time. Remarkably, the distance between the activation seeds is independent of temperature within experimental uncertainty and amounts to several micrometers, a value in close agreement with the crossover length for TPD glasses. We speculate the initiation sites for the transformation of the glass into the supercooled liquid are localized regions of lower stability (or density).
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Affiliation(s)
- A Vila-Costa
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - J Ràfols-Ribé
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - M González-Silveira
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - A F Lopeandia
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Ll Abad-Muñoz
- Instituto de Microelectrónica de Barcelona-Centre Nacional de Microelectrònica, Campus UAB, Bellaterra, Barcelona 08193, Spain
| | - J Rodríguez-Viejo
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
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16
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Rodríguez-Tinoco C, Gonzalez-Silveira M, Ràfols-Ribé J, Vila-Costa A, Martinez-Garcia JC, Rodríguez-Viejo J. Surface-Bulk Interplay in Vapor-Deposited Glasses: Crossover Length and the Origin of Front Transformation. PHYSICAL REVIEW LETTERS 2019; 123:155501. [PMID: 31702315 DOI: 10.1103/physrevlett.123.155501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Thin film stable glasses transform into a liquid by a moving front that propagates from surfaces or interfaces with higher mobility. We use calorimetric data of vapor-deposited glasses of different thicknesses and stabilities to identify the role of glassy and liquid dynamics on the transformation process. By invoking the existence of an ultrathin intermediate layer whose transformation strongly depends on the properties of both the liquid and the glass, we show that the recovery to equilibrium is driven by the mismatch in the dynamics between glass and liquid. The lifetime of this intermediate layer associated with the moving front is the geometric mean between the bulk transformation time and the alpha relaxation time. Within this view, we explain the observed dependencies of the growth front velocity and the crossover length with both stability and temperature. Extrapolation of these results points towards ordinary thin film glasses transforming via a frontlike transformation mechanism if heated sufficiently fast, establishing a close connection between vapor-deposited and liquid-cooled glasses.
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Affiliation(s)
- Cristian Rodríguez-Tinoco
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Marta Gonzalez-Silveira
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Joan Ràfols-Ribé
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Ana Vila-Costa
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Julio Cesar Martinez-Garcia
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Javier Rodríguez-Viejo
- Group of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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17
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Begam N, Das A N, Chandran S, Ibrahim M, Padmanabhan V, Sprung M, Basu JK. Nanoparticle-polymer interfacial layer properties tune fragility and dynamic heterogeneity of athermal polymer nanocomposite films. SOFT MATTER 2018; 14:8853-8859. [PMID: 30357240 DOI: 10.1039/c8sm01729h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Enthalpic interactions at the interface between nanoparticles and matrix polymers are known to influence various properties of the resultant polymer nanocomposites (PNC). For athermal PNCs, consisting of grafted nanoparticles embedded in chemically identical polymers, the role and extent of the interface layer (IL) interactions in determining the properties of the nanocomposites are not very clear. Here, we demonstrate the influence of the interfacial layer dynamics on the fragility and dynamical heterogeneity (DH) of athermal and glassy PNCs. The IL properties are altered by changing the grafted to matrix polymer size ratio, f, which in turn changes the extent of matrix chain penetration into the grafted layer, λ. The fragility of PNCs is found to increase monotonically with increasing entropic compatibility, characterised by increasing λ. Contrary to observations in most polymers and glass formers, we observe an anti-correlation between the dependence on IL dynamics of fragility and DH, quantified by the experimentally estimated Kohlrausch-Watts-Williams parameter and the non-Gaussian parameter obtained from simulations.
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Affiliation(s)
- Nafisa Begam
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India.
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18
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Monnier X, Cangialosi D. Thermodynamic Ultrastability of a Polymer Glass Confined at the Micrometer Length Scale. PHYSICAL REVIEW LETTERS 2018; 121:137801. [PMID: 30312075 DOI: 10.1103/physrevlett.121.137801] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Indexed: 06/08/2023]
Abstract
We employ fast scanning calorimetry to assess the thermodynamic state attained after a given cooling rate and the molecular mobility of glassy poly(4-tert-butylstyrene) confined at the micrometer length scale. We show that, for such a large confinement length scale, thermodynamic states with a fictive temperature (T_{f}) 80 K below the polymer glass transition temperature (T_{g}) are attained, which allows to bypass the geological timescales required for bulk glasses. Access to such states is promoted by a fast mechanism of equilibration. Importantly, the tremendous T_{f} decrease takes place while the molecular mobility remains bulklike, indicating marked decoupling between vitrification kinetics and molecular mobility.
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Affiliation(s)
- Xavier Monnier
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - Daniele Cangialosi
- Centro de Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain and Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
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19
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Vyazovkin S. "Nothing Can Hide Itself from Thy Heat": Understanding Polymers via Unconventional Applications of Thermal Analysis. Macromol Rapid Commun 2018; 40:e1800334. [PMID: 30033550 DOI: 10.1002/marc.201800334] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/26/2018] [Indexed: 11/06/2022]
Abstract
This article surveys some exciting possibilities and results offered by less common, yet essential applications of differential scanning calorimetry and thermogravimetric analysis (TGA). The applications are concerned with the most commonly studied processes of the glass transition, crystallization, melting, polymerization, and degradation. Issues related to the glass transition include the non-Arrhenius temperature dependence and fragility, kinetic complexity of physical aging, evaluation of cooperatively rearranging regions, and rigid amorphous fraction. Discussion of crystallization covers separation of heterogeneous and homogeneous nucleation, crystallization controlled by physical aging, and the use of isoconversional methods for determining the Hoffman-Lauritzen parameters. For melting, the role of reorganization and nucleation control is emphasized. For the thermal degradation and polymerization, advanced kinetic treatments as a way of obtaining mechanistic insights are discussed, and the possibility of studying both processes during continuous cooling is stressed. The possibility of using TGA for monitoring polycondensation is also highlighted.
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Affiliation(s)
- Sergey Vyazovkin
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL, 35294, USA
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20
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Philipp M, Nies C, Ostermeyer M, Possart W, Krüger JK. Thermal glass transition beyond kinetics of a non-crystallizable glass-former. SOFT MATTER 2018; 14:3601-3611. [PMID: 29693663 DOI: 10.1039/c7sm02359f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A long-debated problem related to glass formation in amorphous materials is the interplay of thermodynamic, kinetic and α-relaxation processes. For the first time, low-frequency dynamics, as well as kinetic or quasi-static thermal expansion coefficients of a non-crystallizable glass-former are simultaneously measured. Based on the feedback between low-frequency dynamics and morphology, the study supports the viewpoint that glass formation can be observed in internal equilibrium, i.e. beyond kinetics, and might stem from spontaneous local-scale morphological changes.
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Affiliation(s)
- Martine Philipp
- Universität des Saarlandes, Lehrstuhl Adhäsion & Interphasen in Polymeren, Gebäude C6.3, D-66041 Saarbrücken, Germany.
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21
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Perez-De-Eulate NG, Cangialosi D. Double Mechanism for Structural Recovery of Polystyrene Nanospheres. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00502] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Natalia G. Perez-De-Eulate
- Centro de Física
de Materiales CFM (CSIC-UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - Daniele Cangialosi
- Centro de Física
de Materiales CFM (CSIC-UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Donostia
International
Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
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22
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Li D, Yang J, Zhao J. Positioning a fluorescent probe at the core of a glassy star polymer for detection of local dynamics. CHINESE CHEM LETT 2018. [DOI: 10.1016/j.cclet.2017.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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23
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Cangialosi D. Glass Transition and Physical Aging of Confined Polymers Investigated by Calorimetric Techniques. RECENT ADVANCES, TECHNIQUES AND APPLICATIONS 2018. [DOI: 10.1016/b978-0-444-64062-8.00013-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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24
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Perez-De Eulate NG, Cangialosi D. The very long-term physical aging of glassy polymers. Phys Chem Chem Phys 2018; 20:12356-12361. [DOI: 10.1039/c8cp01940a] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The thermodynamic state of polymer glasses aged over 30 years reveals the existence of a metastable state with partial equilibrium recovery.
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Affiliation(s)
| | - Daniele Cangialosi
- Centro de Física de Materiales
- 20018 San Sebastián
- Spain
- Donostia International Physics Center (DIPC)
- San Sebastián
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25
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Boucher VM, Cangialosi D, Alegría A, Colmenero J. Complex nonequilibrium dynamics of stacked polystyrene films deep in the glassy state. J Chem Phys 2017; 146:203312. [DOI: 10.1063/1.4977207] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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26
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Wisitsorasak A, Wolynes PG. Dynamical theory of shear bands in structural glasses. Proc Natl Acad Sci U S A 2017; 114:1287-1292. [PMID: 28108571 PMCID: PMC5307478 DOI: 10.1073/pnas.1620399114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The heterogeneous elastoplastic deformation of structural glasses is explored using the framework of the random first-order transition theory of the glass transition along with an extended mode-coupling theory that includes activated events. The theory involves coupling the continuum elastic theory of strain transport with mobility generation and transport as described in the theory of glass aging and rejuvenation. Fluctuations that arise from the generation and transport of mobility, fictive temperature, and stress are treated explicitly. We examine the nonlinear flow of a glass under deformation at finite strain rate. The interplay among the fluctuating fields leads to the spatially heterogeneous dislocation of the particles in the glass, i.e., the appearance of shear bands of the type observed in metallic glasses deforming under mechanical stress.
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Affiliation(s)
- Apiwat Wisitsorasak
- Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
- Theoretical and Computational Physics Group, Theoretical and Computational Science Center, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Peter G Wolynes
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005;
- Department of Physics & Astronomy, Rice University, Houston, TX 77005
- Department of Chemistry, Rice University, Houston, TX 77005
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27
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Boucher VM, Cangialosi D, Alegría A, Colmenero J. Reaching the ideal glass transition by aging polymer films. Phys Chem Chem Phys 2017; 19:961-965. [DOI: 10.1039/c6cp07139b] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
By aging, we draw glassy polymer films to a thermodynamic state, the ideal glass, with the entropy of the crystal.
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Affiliation(s)
| | | | - Angel Alegría
- Centro de Física de Materiales
- 20018 San Sebastián
- Spain
- Departamento de Física de Materiales (UPV/EHU)
- 20080 San Sebastián
| | - Juan Colmenero
- Centro de Física de Materiales
- 20018 San Sebastián
- Spain
- Departamento de Física de Materiales (UPV/EHU)
- 20080 San Sebastián
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28
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Yu HB, Richert R, Samwer K. Correlation between Viscoelastic Moduli and Atomic Rearrangements in Metallic Glasses. J Phys Chem Lett 2016; 7:3747-3751. [PMID: 27606965 DOI: 10.1021/acs.jpclett.6b01738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Dynamical moduli, such as storage and loss moduli, characterize the viscoelasticity of materials (i.e., time-dependent elasticity) and convey important information about the relaxation processes of glasses and supercooled liquids. A fundamental question is what ultimately determines them in glassy materials. Here, for several model metallic glasses, we demonstrate that both the storage and loss moduli are uniquely determined by the most probable atomic nonaffine displacements, regardless of temperature or frequency. Moreover, the fast-moving atoms (which contribute to dynamical heterogeneity) do not contribute explicitly to the moduli. Our findings provide a physical basis for the origin of viscoelasticity in metallic glasses.
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Affiliation(s)
- Hai-Bin Yu
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , WuHan 430074, China
| | - Ranko Richert
- School of Molecular Sciences, Arizona State University , Tempe, Arizona 85287, United States
| | - Konrad Samwer
- I. Physikalisches Institut, Universität Göttingen , D-37077 Göttingen, Germany
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29
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Jack RL, Berthier L. The melting of stable glasses is governed by nucleation-and-growth dynamics. J Chem Phys 2016; 144:244506. [PMID: 27369526 DOI: 10.1063/1.4954327] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We discuss the microscopic mechanisms by which low-temperature amorphous states, such as ultrastable glasses, transform into equilibrium fluids, after a sudden temperature increase. Experiments suggest that this process is similar to the melting of crystals, thus differing from the behaviour found in ordinary glasses. We rationalize these observations using the physical idea that the transformation process takes place close to a "hidden" equilibrium first-order phase transition, which is observed in systems of coupled replicas. We illustrate our views using simulation results for a simple two-dimensional plaquette spin model, which is known to exhibit a range of glassy behaviour. Our results suggest that nucleation-and-growth dynamics, as found near ordinary first-order transitions, is also the correct theoretical framework to analyse the melting of ultrastable glasses. Our approach provides a unified understanding of multiple experimental observations, such as propagating melting fronts, large kinetic stability ratios, and "giant" dynamic length scales. We also provide a comprehensive discussion of available theoretical pictures proposed in the context of ultrastable glass melting.
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Affiliation(s)
- Robert L Jack
- Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
| | - Ludovic Berthier
- Laboratoire Charles Coulomb, UMR 5221 CNRS-Université de Montpellier, 34095 Montpellier, France
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30
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Tu W, Li X, Chen Z, Liu YD, Labardi M, Capaccioli S, Paluch M, Wang LM. Glass formability in medium-sized molecular systems/pharmaceuticals. I. Thermodynamics vs. kinetics. J Chem Phys 2016; 144:174502. [PMID: 27155640 DOI: 10.1063/1.4947476] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Scrutinizing critical thermodynamic and kinetic factors for glass formation and the glass stability of materials would benefit the screening of the glass formers for the industry of glassy materials. The present work aims at elucidating the factors that contribute to the glass formation by investigating medium-sized molecules of pharmaceuticals. Glass transition related thermodynamics and kinetics are performed on the pharmaceuticals using calorimetric, dielectric, and viscosity measurements. The characteristic thermodynamic and kinetic parameters of glass transition are found to reproduce the relations established for small-molecule glass formers. The systematic comparison of the thermodynamic and kinetic contributions to glass formation reveals that the melting-point viscosity is the crucial quantity for the glass formation. Of more interest is the finding of a rough correlation between the melting-point viscosity and the entropy of fusion normalized by the number of beads of the pharmaceuticals, suggesting the thermodynamics can partly manifest its contribution to glass formation via kinetics.
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Affiliation(s)
- Wenkang Tu
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China
| | - Xiangqian Li
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China
| | - Zeming Chen
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China
| | - Ying Dan Liu
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China
| | | | - Simone Capaccioli
- CNR-IPCF, Sede Secondaria Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
| | - M Paluch
- Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
| | - Li-Min Wang
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China
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31
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Abstract
Glasses are out-of-equilibrium systems aging under the crystallization threat. During ordinary glass formation, the atomic diffusion slows down, rendering its experimental investigation impractically long, to the extent that a timescale divergence is taken for granted by many. We circumvent these limitations here, taking advantage of a wide family of glasses rapidly obtained by physical vapor deposition directly into the solid state, endowed with different "ages" rivaling those reached by standard cooling and waiting for millennia. Isothermally probing the mechanical response of each of these glasses, we infer a correspondence with viscosity along the equilibrium line, up to exapoise values. We find a dependence of the elastic modulus on the glass age, which, traced back to the temperature steepness index of the viscosity, tears down one of the cornerstones of several glass transition theories: the dynamical divergence. Critically, our results suggest that the conventional wisdom picture of a glass ceasing to flow at finite temperature could be wrong.
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32
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Das AK. Exploring the glass transition region: crowding effect, nonergodicity and thermorheological complexity. Phys Chem Chem Phys 2015; 17:16110-24. [DOI: 10.1039/c5cp00301f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thermorheological complexity in polystyrene near the glass transition point has been created through Monte Carlo simulations.
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Affiliation(s)
- Ashok K. Das
- School of Mechanical Engineering
- Gyeongsang National University
- Jinju
- South Korea
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33
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WITHDRAWN: Thermorheological complexity revisited: A simple Monte Carlo simulation scheme to create the near Tg behavior in linear homopolymer melts. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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