1
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Novikov VN. Temperature dependence of spatial nanoheterogeneities of shear modulus in supercooled glycerol. J Chem Phys 2024; 161:054501. [PMID: 39087539 DOI: 10.1063/5.0215095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 07/15/2024] [Indexed: 08/02/2024] Open
Abstract
The boson peak in the terahertz vibrational spectrum carries information about nano-heterogeneities in the shear modulus in glass formers. Its evolution upon heating or cooling in a supercooled liquid state may shed light on the temperature dependence of heterogeneities. For this purpose, an analysis of the light scattering spectra of supercooled glycerol in the spectral range of the boson peak and fast relaxation was carried out and the parameters of the boson peak in the temperature range 180-330 K were determined. The temperature dependent frequency of the boson peak was then expressed in terms of the mean-square amplitude of the shear modulus fluctuations. This was done using the heterogeneous elasticity theory in combination with the perturbation theory on small fluctuations and Ioffe-Regel criterion for transverse vibrations in glass formers. The contribution of structural relaxation effects to phonon damping becomes significant with increasing temperature. It is shown here that structural relaxation largely determines the temperature dependence of the mean-square fluctuations of the shear modulus at high temperatures. By solving the inverse problem, the temperature dependence of shear modulus fluctuations was obtained. It shows a rapid decrease above ∼250 K with a linear extrapolation going to zero at the so-called Arrhenius temperature TA = 350 K. Comparison with literature data on the Landau-Placzek ratio shows that they have a similar temperature dependence at T < TA, which is explained by the appearance of nanometer scale spatial heterogeneities below TA. This is confirmed by the temperature dependence of the amplitude of the boson peak.
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Affiliation(s)
- V N Novikov
- Institute of Automation and Electrometry of the Russian Academy of Sciences, 1 Koptyug Ave., Novosibirsk 630090, Russia
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2
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Chimenti RV, Lehman-Chong AM, Sepcic AM, Engelhardt JD, Carriere JT, Bensley KA, Markashevsky A, Tu J, Stanzione JF, Lofland SE. Method for determining resin cure kinetics with low-frequency Raman spectroscopy. Analyst 2023; 148:5698-5706. [PMID: 37823883 DOI: 10.1039/d3an01099f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Characterizing resin extent of cure kinetics is critical to understanding the structure-property-processing relationships of polymers. The disorder band present in the low-frequency region of the Raman spectrum is directly related to conformational entropy and the modulus of amorphous materials, both of which change as the resin polymerizes. Normalizing the disorder band to its shoulder (∼85 cm-1) provides structural conversion kinetics, which we can directly correlate to chemical conversion kinetics for methacrylate and epoxy-amine based resin systems. In addition to fitting both the structural and chemical conversion data to a phenomenological kinetic rate equation, we also demonstrate a relationship between the chemical and structural kinetics which appears to relate to the softness of the material. Lastly, we use the method to investigate a methacrylate/epoxy interpenetrating polymer network resin system. We find that the structural and chemical conversions occur simultaneously during the formation of the primary (methacrylate) network, but there is a lag between the two during the formation of the secondary (epoxy-amine) network.
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Affiliation(s)
- Robert V Chimenti
- Department of Physics & Astronomy, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
- Advanced Materials & Manufacturing Institute (AMMI), Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
| | - Alexandra M Lehman-Chong
- Advanced Materials & Manufacturing Institute (AMMI), Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
- Department of Chemical Engineering, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
| | - Alyssa M Sepcic
- Department of Mechanical Engineering, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
| | - Jamison D Engelhardt
- Department of Physics & Astronomy, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
- Advanced Materials & Manufacturing Institute (AMMI), Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
| | - James T Carriere
- Coherent Inc., 850 East Duarte Road, Monrovia, California 91016, USA
| | - Kayla A Bensley
- Department of Physics & Astronomy, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Adam Markashevsky
- Department of Mechanical Engineering, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
| | - Jianwei Tu
- Advanced Materials & Manufacturing Institute (AMMI), Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
| | - Joseph F Stanzione
- Advanced Materials & Manufacturing Institute (AMMI), Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
- Department of Chemical Engineering, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
| | - Samuel E Lofland
- Department of Physics & Astronomy, Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
- Advanced Materials & Manufacturing Institute (AMMI), Rowan University, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA
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3
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Zhang H, Wang X, Yu HB, Douglas JF. Fast dynamics in a model metallic glass-forming material. J Chem Phys 2021; 154:084505. [DOI: 10.1063/5.0039162] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Xinyi Wang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Hai-Bin Yu
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jack F. Douglas
- Material Measurement Laboratory, Material Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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4
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Soles CL, Burns AB, Ito K, Chan EP, Douglas JF, Wu J, Yee AF, Shih YT, Huang L, Dimeo RM, Tyagi M. Why Enhanced Subnanosecond Relaxations Are Important for Toughness in Polymer Glasses. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02574] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Christopher L. Soles
- NIST Materials Science and Engineering Division, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Adam B. Burns
- NIST Materials Science and Engineering Division, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Kanae Ito
- NIST Materials Science and Engineering Division, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Edwin P. Chan
- NIST Materials Science and Engineering Division, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Jack F. Douglas
- NIST Materials Science and Engineering Division, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Jinhuang Wu
- Macromolecular Science and Engineering Program, University of Michigan, 2800 Plymouth Road, Ann Arbor, Michigan 48109, United States
| | - Albert F. Yee
- Department of Chemical and Biological Engineering, University of California, Irvine, California 92697, United States
| | - Yueh-Ting Shih
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
| | - Liping Huang
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
| | - Robert M. Dimeo
- NIST Center for Neutron Research, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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5
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Role of Anharmonic Interactions for Vibration Density of States in α-Cristobalite. MATERIALS 2021; 14:ma14030617. [PMID: 33572842 PMCID: PMC7866241 DOI: 10.3390/ma14030617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 11/29/2022]
Abstract
The vibrational density of states (VDOS) of solids in the low-energy regime controls the thermal and transport properties of materials, such as heat capacity, heat conduction, free energy and entropy. In α-Cristobalite, the low-frequency part of vibration density of states (VDOS) has many common features with the Boson peak in silica glass of matched densities. Recent theoretical work reported that anharmonic phonon–phonon interactions were critical for the low-frequency part of VDOS in α-Cristobalite. Therefore, it is urgent to identify the role of different anharmonic interactions from first principles. In this paper, we focus on the main peak of the low-frequency part of VDOS in α-Cristobalite. Calculated by our own developed codes and first principles, we find that the quartic anharmonic interaction can increase the frequency of the peak, while the cubic anharmonic can reduce the frequency and change the shape of the peak. Meanwhile, the anharmonic interactions are critical for the temperature effect. Therefore, we calculated the temperature-dependent property of the peak. We find that the frequency of the peak is directly proportional to the temperature. The atomic displacement patterns of different temperatures also confirm the above conclusion. All our calculations converged well. Moreover, our basic results agree well with other published results. Finally, we highlight that our codes offer a general and reliable way to calculate the VDOS with temperature.
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The Proton Density of States in Confined Water (H 2O). Int J Mol Sci 2019; 20:ijms20215373. [PMID: 31671726 PMCID: PMC6861890 DOI: 10.3390/ijms20215373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/17/2019] [Accepted: 10/24/2019] [Indexed: 12/05/2022] Open
Abstract
The hydrogen density of states (DOS) in confined water has been probed by inelastic neutron scattering spectra in a wide range of its P–T phase diagram. The liquid–liquid transition and the dynamical crossover from the fragile (super-Arrhenius) to strong (Arrhenius) glass forming behavior have been studied, by taking into account the system polymorphism in both the liquid and amorphous solid phases. The interest is focused in the low energy region of the DOS (E<10 meV) and the data are discussed in terms of the energy landscape (local minima of the potential energy) approach. In this latest research, we consider a unit scale energy (EC) linked to the water local order governed by the hydrogen bonding (HB). All the measured spectra, scaled according to such energy, evidence a universal power law behavior with different exponents (γ) in the strong and fragile glass forming regions, respectively. In the first case, the DOS data obey the Debye squared-frequency law, whereas, in the second one, we obtain a value predicted in terms of the mode-coupling theory (MCT) (γ≃1.6).
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8
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Baggioli M, Zaccone A. Universal Origin of Boson Peak Vibrational Anomalies in Ordered Crystals and in Amorphous Materials. PHYSICAL REVIEW LETTERS 2019; 122:145501. [PMID: 31050477 DOI: 10.1103/physrevlett.122.145501] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/11/2019] [Indexed: 06/09/2023]
Abstract
The vibrational spectra of solids, both ordered and amorphous, in the low-energy regime, control the thermal and transport properties of materials, from heat capacity to heat conduction, electron-phonon couplings, conventional superconductivity, etc. The old Debye model of vibrational spectra at low energy gives the vibrational density of states (VDOS) as proportional to the frequency squared, but in many materials the spectrum departs from this law which results in a peak upon normalizing the VDOS by frequency squared, which is known as the "boson peak." A description of the VDOS of solids (both crystals and glasses) is presented starting from first principles. Without using any assumptions whatsoever of disorder in the material, it is shown that the boson peak in the VDOS of both ordered crystals and glasses arises naturally from the competition between elastic mode propagation and diffusive damping. The theory explains the recent experimental observations of boson peak in perfectly ordered crystals, which cannot be explained based on previous theoretical frameworks. The theory also explains, for the first time, how the vibrational spectrum changes with the atomic density of the solid, and explains recent experimental observations of this effect.
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Affiliation(s)
- Matteo Baggioli
- Instituto de Fisica Teorica UAM/CSIC, c/Nicolas Cabrera 13-15, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- Crete Center for Theoretical Physics, Institute for Theoretical and Computational Physics, Department of Physics, University of Crete, 71003 Heraklion, Greece
| | - Alessio Zaccone
- Department of Physics "A. Pontremoli", University of Milan, via Celoria 16, 20133 Milan, Italy
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, CB30HE Cambridge, United Kingdom
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB30AS Cambridge, United Kingdom
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Abstract
Molecular dynamics (MD) simulations of five ionic liquids based on 1-alkyl-3-methylimidazolium cations, [C n C1im]+, have been performed in order to calculate high-frequency elastic moduli and to evaluate heterogeneity of local elastic moduli. The MD simulations of [C n C1im][NO3], n = 2, 4, 6, and 8, assessed the effect of domain segregation when the alkyl chain length increases, and [C8C1im][PF6] assessed the effect of strength of anion-cation interaction. Dispersion curves of excitation energies of longitudinal and transverse acoustic, LA and TA, modes were obtained from time correlation functions of mass currents at different wavevectors. High-frequency sound velocity of LA modes depends on the alkyl chain length, but sound velocity for TA modes does not. High-frequency bulk and shear moduli, K ∞ and G ∞ , depend on the alkyl chain length because of a density effect. Both K ∞ and G ∞ are strongly dependent on the anion. The calculation of local bulk and shear moduli was accomplished by performing bulk and shear deformations of the systems cooled to 0 K. The simulations showed a clear connection between structural and elastic modulus heterogeneities. The development of nano-heterogeneous structure with increasing length of the alkyl chain in [C n C1im][NO3] implies lower values for local bulk and shear moduli in the non-polar domains. The mean value and the standard deviations of distributions of local elastic moduli decrease when [NO3]- is replaced by the less coordinating [PF6]- anion.
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Affiliation(s)
- Arno A Veldhorst
- Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-000, Brazil
| | - Mauro C C Ribeiro
- Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-000, Brazil
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11
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Baldi G, Benassi P, Fontana A, Giugni A, Monaco G, Nardone M, Rossi F. Damping of vibrational excitations in glasses at terahertz frequency: The case of 3-methylpentane. J Chem Phys 2017; 147:164501. [PMID: 29096506 DOI: 10.1063/1.4998696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report a compared analysis of inelastic X ray scattering (IXS) and of low frequency Raman data of glassy 3-methylpentane. The IXS spectra have been analysed allowing for the existence of two distinct excitations at each scattering wavevector obtaining a consistent interpretation of the spectra. In particular, this procedure allows us to interpret the linewidth of the modes in terms of a simple model which relates them to the width of the first sharp diffraction peak in the static structure factor. In this model, the width of the modes arises from the blurring of the dispersion curves which increases approaching the boundary of the first pseudo-Brillouin zone. The position of the boson peak contribution to the density of vibrational states derived from the Raman scattering measurements is in agreement with the interpretation of the two excitations in terms of a longitudinal mode and a transverse mode, the latter being a result of the mixed character of the transverse modes away from the center of the pseudo-Brillouin zone.
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Affiliation(s)
- Giacomo Baldi
- Dipartimento di Fisica, Università di Trento, 38050 Povo, Trento, Italy
| | - Paola Benassi
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila, 67100 L'Aquila, Italy
| | - Aldo Fontana
- Dipartimento di Fisica, Università di Trento, 38050 Povo, Trento, Italy
| | - Andrea Giugni
- PSE and BESE Divisions, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Giulio Monaco
- Dipartimento di Fisica, Università di Trento, 38050 Povo, Trento, Italy
| | - Michele Nardone
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila, 67100 L'Aquila, Italy
| | - Flavio Rossi
- Dipartimento di Fisica, Università di Trento, 38050 Povo, Trento, Italy
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12
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Lin J, Jorjadze I, Pontani LL, Wyart M, Brujic J. Evidence for Marginal Stability in Emulsions. PHYSICAL REVIEW LETTERS 2016; 117:208001. [PMID: 27886471 DOI: 10.1103/physrevlett.117.208001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Indexed: 06/06/2023]
Abstract
We report the first measurements of the effect of pressure on vibrational modes in emulsions, which serve as a model for soft frictionless spheres at zero temperature. As a function of the applied pressure, we find that the density of states D(ω) exhibits a low-frequency cutoff ω^{*}, which scales linearly with the number of extra contacts per particle δz. Moreover, for ω<ω^{*}, our results are consistent with D(ω)∼ω^{2}/ω^{*2}, a quadratic behavior whose prefactor is larger than what is expected from Debye theory. This surprising result agrees with recent theoretical findings [E. DeGiuli, A. Laversanne-Finot, G. A. Düring, E. Lerner, and M. Wyart, Soft Matter 10, 5628 (2014); S. Franz, G. Parisi, P. Urbani, and F. Zamponi, Proc. Natl. Acad. Sci. U.S.A. 112, 14539 (2015)]. Finally, the degree of localization of the softest low frequency modes increases with compression, as shown by the participation ratio as well as their spatial configurations. Overall, our observations show that emulsions are marginally stable and display non-plane-wave modes up to vanishing frequencies.
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Affiliation(s)
- Jie Lin
- Center for Soft Matter Research, Department of Physics, New York University, New York, New York 10003, USA
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Ivane Jorjadze
- Center for Soft Matter Research, Department of Physics, New York University, New York, New York 10003, USA
| | - Lea-Laetitia Pontani
- Center for Soft Matter Research, Department of Physics, New York University, New York, New York 10003, USA
- Institut des Nanosciences de Paris, UMR 7588-CNRS/Universite Pierre et Marie Curie, 75005 Paris, France
| | - Matthieu Wyart
- Physics Institute, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne, Switzerland
| | - Jasna Brujic
- Center for Soft Matter Research, Department of Physics, New York University, New York, New York 10003, USA
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13
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Dalle-Ferrier C, Kisliuk A, Hong L, Carini G, Carini G, D’Angelo G, Alba-Simionesco C, Novikov VN, Sokolov AP. Why many polymers are so fragile: A new perspective. J Chem Phys 2016; 145:154901. [DOI: 10.1063/1.4964362] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- C. Dalle-Ferrier
- Laboratoire Léon Brillouin, UMR 12, CEA-CNRS, 91191 Saclay, France
| | - A. Kisliuk
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L. Hong
- Institute of Natural Sciences & Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - G. Carini
- IPCF del CNR, UOS di Messina, I-98158 Messina, Italy
| | - G. Carini
- Dipartimento di Fisica e Scienze della Terra, Università di Messina, I-98166 Messina, Italy
| | - G. D’Angelo
- Dipartimento di Fisica e Scienze della Terra, Università di Messina, I-98166 Messina, Italy
| | | | - V. N. Novikov
- Department of Chemistry and Joint Institute for Neutron Sciences, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - A. P. Sokolov
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Chemistry and Joint Institute for Neutron Sciences, University of Tennessee, Knoxville, Tennessee 37996, USA
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14
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Ishikawa MS, Lima TA, Ferreira FF, Martinho HS. Unusual specific heat of almost dry L-cysteine and L-cystine amino acids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:032709. [PMID: 25871146 DOI: 10.1103/physreve.91.032709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Indexed: 06/04/2023]
Abstract
A detailed quantitative analysis of the specific heat in the 0.5- to 200-K temperature range for almost dry L-cysteine and its dimer, L-cystine, amino acids is presented. We report the occurrence of a sharp first-order transition at ∼76 K for L-cysteine associated with the thiol group ordering which was successfully modeled with the two-dimensional Ising model. We demonstrated that quantum rotors, two-level systems (TLS), Einstein oscillators, and acoustic phonons (the Debye model) are essential ingredients to correctly describe the overall experimental data. Our analysis pointed out the absence of the TLS contribution to the low temperature specific heat of L-cysteine. This result was similar to that found in other noncrystalline amorphous materials, e.g., amorphous silicon, low density amorphous water, and ultrastable glasses. L-cystine presented an unusual nonlinear acoustic dispersion relation ω(q)=vq0.95 and a Maxwell-Boltzmann-type distribution of tunneling barriers. The presence of Einstein oscillators with ΘE∼70 K was common in both systems and adequately modeled the boson peak contributions.
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Affiliation(s)
- M S Ishikawa
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados, 5001, Santo André-SP, BR-09210-580, Brazil
| | - T A Lima
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados, 5001, Santo André-SP, BR-09210-580, Brazil
| | - F F Ferreira
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados, 5001, Santo André-SP, BR-09210-580, Brazil
| | - H S Martinho
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados, 5001, Santo André-SP, BR-09210-580, Brazil
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15
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Perticaroli S, Russo D, Paolantoni M, Gonzalez MA, Sassi P, Nickels JD, Ehlers G, Comez L, Pellegrini E, Fioretto D, Morresi A. Painting biological low-frequency vibrational modes from small peptides to proteins. Phys Chem Chem Phys 2015; 17:11423-31. [DOI: 10.1039/c4cp05388e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We use experiments and simulation to investigate the validity of different model systems used to study the low-frequency vibrations of proteins.
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Affiliation(s)
- S. Perticaroli
- Joint Institute for Neutron Sciences
- Oak Ridge National Laboratory
- Oak Ridge
- USA
- Chemical and Materials Sciences Division
| | - D. Russo
- CNR-IOM
- Italy c/o Institut Laue Langevin
- France
- Institut Lumière Matière
- Université de Lyon 1
| | - M. Paolantoni
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- I-06123 Perugia
- Italy
| | | | - P. Sassi
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- I-06123 Perugia
- Italy
| | - J. D. Nickels
- Joint Institute for Neutron Sciences
- Oak Ridge National Laboratory
- Oak Ridge
- USA
- Department of Chemistry
| | - G. Ehlers
- Quantum Condensed Matter Division
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - L. Comez
- IOM-CNR c/o Dipartimento di Fisica e Geologia
- Università di Perugia
- I-06123 Perugia
- Italy
- Dipartimento di Fisica e Geologia
| | | | - D. Fioretto
- Dipartimento di Fisica e Geologia
- Università di Perugia
- I-06123 Perugia
- Italy
- Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN)
| | - A. Morresi
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- I-06123 Perugia
- Italy
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16
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Low-temperature excess heat capacity in fresnoite glass and crystal. Sci Rep 2014; 4:6523. [PMID: 25283583 PMCID: PMC4185376 DOI: 10.1038/srep06523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 09/12/2014] [Indexed: 11/17/2022] Open
Abstract
The effect of thermal annealing on low-temperature excess heat capacity was investigated in fresnoite (Ba2TiSi2O8) glass. The amplitudes of the excess heat capacity decreased, and their positions shifted to a higher temperature by relaxation or crystallization. In particular, we revealed that the change in the excess heat capacity during transition from the glassy state to the crystalline state is relatively small compared with that of other oxides. Therefore, it is suggested that distribution of the excess vibrational density of states of the glass is similar to that of the corresponding crystal.
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17
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Adichtchev SV, Malinovsky VK, Ignatieva LN, Merkulov EB, Surovtsev NV. Low-frequency inelastic light scattering in a ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass. J Chem Phys 2014; 140:184508. [PMID: 24832289 DOI: 10.1063/1.4875095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Low-frequency (down to 30 GHz) inelastic light scattering is studied in a multicomponent glass ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) in a wide temperature range. The contributions of the THz vibrational spectrum (boson peak) and of the fast relaxation are extracted and analyzed. It is shown that the fast relaxation spectrum is described by a distribution of relaxation times leading to a power-law ν(α) dependence in the frequency range 30-300 GHz. Temperature dependence of α(T) is well described by the Gilroy-Phillips model, while the integrated intensity of the fast relaxation increases significantly with the temperature. This feature distinguishes the fast relaxation in ZBLAN from the case of most single-component glasses. Thermodynamic and kinetic fragility indexes are significantly different for the ZBLAN glass. The correlations between the boson peak intensity, elastic moduli, and fragility index, found earlier for single-component glasses, are fulfilled for the thermodynamic fragility index of ZBLAN. In contrast, the correlation between the fast relaxation intensity at Tg and the fragility holds better for the kinetic fragility index of ZBLAN. We propose that thermodynamic and kinetic fragilities reflect different aspects of glassy dynamics in the case of glass formers with the complex chemical composition and structure topology: the former correlates with the elastic properties and the boson peak, the latter with the relaxation.
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Affiliation(s)
- S V Adichtchev
- Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - V K Malinovsky
- Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - L N Ignatieva
- Institute of Chemistry, Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - E B Merkulov
- Institute of Chemistry, Far East Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - N V Surovtsev
- Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia
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18
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Wang L, Xu N. Probing the glass transition from structural and vibrational properties of zero-temperature glasses. PHYSICAL REVIEW LETTERS 2014; 112:055701. [PMID: 24580613 DOI: 10.1103/physrevlett.112.055701] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Indexed: 06/03/2023]
Abstract
We find that the density dependence of the glass transition temperature of Lennard-Jones (LJ) and Weeks-Chandler-Andersen (WCA) systems can be predicted from properties of the zero-temperature (T=0) glasses. Below a crossover density ρs, LJ and WCA glasses show different structures, leading to different vibrational properties and consequently making LJ glasses more stable with higher glass transition temperatures than WCA ones. Above ρs, structural and vibrational quantities of the T=0 glasses show scaling collapse. From scaling relations and dimensional analysis, we predict a density scaling of the glass transition temperature, in excellent agreement with simulation results. We also propose an empirical expression of the glass transition temperature using structural and vibrational properties of the T=0 glasses, which works well over a wide range of densities.
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Affiliation(s)
- Lijin Wang
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Ning Xu
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
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19
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Corezzi S, Caponi S, Rossi F, Fioretto D. Stress-Induced Modification of the Boson Peak Scaling Behavior. J Phys Chem B 2013; 117:14477-85. [DOI: 10.1021/jp4054742] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Silvia Corezzi
- Dipartimento
di Fisica, Universitá di Perugia, Via A. Pascoli, Perugia 06123, Italy
| | - Silvia Caponi
- Dipartimento
di Fisica, Universitá di Trento, Via Sommarive 14, Povo (Trento) 38123, Italy
- IOM-CNR
c/o Dipartimento di Fisica, Universitá di Perugia, Via A. Pascoli, Perugia 06123, Italy
| | - Flavio Rossi
- Dipartimento
di Fisica, Universitá di Trento, Via Sommarive 14, Povo (Trento) 38123, Italy
| | - Daniele Fioretto
- Dipartimento
di Fisica, Universitá di Perugia, Via A. Pascoli, Perugia 06123, Italy
- Centro
di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), Universitá di Perugia, via Elce di Sotto 8, Perugia 06123, Italy
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20
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Perticaroli S, Nickels JD, Ehlers G, O'Neill H, Zhang Q, Sokolov AP. Secondary structure and rigidity in model proteins. SOFT MATTER 2013; 9:9548-56. [PMID: 26029761 DOI: 10.1039/c3sm50807b] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
There is tremendous interest in understanding the role that secondary structure plays in the rigidity and dynamics of proteins. In this work we analyze nanomechanical properties of proteins chosen to represent different secondary structures: α-helices (myoglobin and bovine serum albumin), β-barrels (green fluorescent protein), and α + β + loop structures (lysozyme). Our experimental results show that in these model proteins, the β motif is a stiffer structural unit than the α-helix in both dry and hydrated states. This difference appears not only in the rigidity of the protein, but also in the amplitude of fast picosecond fluctuations. Moreover, we show that for these examples the secondary structure correlates with the temperature- and hydration-induced changes in the protein dynamics and rigidity. Analysis also suggests a connection between the length of the secondary structure (α-helices) and the low-frequency vibrational mode, the so-called boson peak. The presented results suggest an intimate connection of dynamics and rigidity with the protein secondary structure.
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Affiliation(s)
- Stefania Perticaroli
- aChemical and Materials Sciences Division at Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. E-mail:
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21
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Zanatta M, Baldi G, Caponi S, Fontana A, Petrillo C, Rossi F, Sacchetti F. Debye to non-Debye scaling of the Boson peak dynamics: Critical behavior and local disorder in vitreous germania. J Chem Phys 2011; 135:174506. [DOI: 10.1063/1.3656697] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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22
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Orsingher L, Fontana A, Gilioli E, Carini G, Carini G, Tripodo G, Unruh T, Buchenau U. Vibrational dynamics of permanently densified GeO2 glasses: Densification-induced changes in the boson peak. J Chem Phys 2010; 132:124508. [DOI: 10.1063/1.3360039] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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23
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Masciovecchio C, Mazzacurati V, Monaco G, Ruocco G, Scopigno T, Sette F, Benassi P, Cunsolo A, Fontana A, Krisch M, Mermet A, Montagna M, Rossi F, Sampoli M, Signorelli G, Verbeni R. Acoustic nature of the boson peak in vitreous silica. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13642819908223089] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- C. Masciovecchio
- a European Synchrotron Radiation Facility , BP 220, F-38043, Grenoble , Cedex , France
| | - V. Mazzacurati
- b Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Università dell'Aquila , I-67100, L'Aquila , Italy
| | - G. Monaco
- b Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Università dell'Aquila , I-67100, L'Aquila , Italy
| | - G. Ruocco
- b Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Università dell'Aquila , I-67100, L'Aquila , Italy
| | - T. Scopigno
- b Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Università dell'Aquila , I-67100, L'Aquila , Italy
| | - F. Sette
- a European Synchrotron Radiation Facility , BP 220, F-38043, Grenoble , Cedex , France
| | - P. Benassi
- b Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Università dell'Aquila , I-67100, L'Aquila , Italy
| | - A. Cunsolo
- a European Synchrotron Radiation Facility , BP 220, F-38043, Grenoble , Cedex , France
| | - A. Fontana
- c Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Universitá di Trento , I-38100, Trento , Italy
| | - M. Krisch
- a European Synchrotron Radiation Facility , BP 220, F-38043, Grenoble , Cedex , France
| | - A. Mermet
- a European Synchrotron Radiation Facility , BP 220, F-38043, Grenoble , Cedex , France
| | - M. Montagna
- c Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Universitá di Trento , I-38100, Trento , Italy
| | - F. Rossi
- c Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Universitá di Trento , I-38100, Trento , Italy
| | - M. Sampoli
- d Dipartimento di Energetica and Istituto Nazionale per la Fisica delia Materia , Universitá di Firenze , I-50139, Firenze , Italy
| | - G. Signorelli
- b Dipartimento di Fisica and Istituto Nazionale per la Fisica delia Materia , Università dell'Aquila , I-67100, L'Aquila , Italy
| | - R. Verbeni
- a European Synchrotron Radiation Facility , BP 220, F-38043, Grenoble , Cedex , France
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24
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Sokolov AP. Fast dynamics in glasses: Relation between the boson peak and quasielastic scattering. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13642819808204961] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- A. P. Sokolov
- a Institut für Festkörperforschung, Forschungszentrum Jülich , D-52425 , Jülich , Germany
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25
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Xu N, Vitelli V, Wyart M, Liu AJ, Nagel SR. Energy transport in jammed sphere packings. PHYSICAL REVIEW LETTERS 2009; 102:038001. [PMID: 19257396 DOI: 10.1103/physrevlett.102.038001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Indexed: 05/27/2023]
Abstract
We calculate the normal modes of vibration in jammed sphere packings to obtain the energy diffusivity, a spectral measure of transport. At the boson peak frequency, we find an Ioffe-Regel crossover from a diffusivity that drops rapidly with frequency to one that is nearly frequency independent. This crossover frequency shifts to zero as the system is decompressed towards the jamming transition, providing unambiguous evidence of a regime in frequency of nearly constant diffusivity. Such a regime, postulated to exist in glasses to explain the temperature dependence of the thermal conductivity, therefore appears to arise from properties of the jamming transition.
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Affiliation(s)
- Ning Xu
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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26
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Caponi S, Corezzi S, Fioretto D, Fontana A, Monaco G, Rossi F. Raman-scattering measurements of the vibrational density of states of a reactive mixture during polymerization: effect on the boson peak. PHYSICAL REVIEW LETTERS 2009; 102:027402. [PMID: 19257317 DOI: 10.1103/physrevlett.102.027402] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2008] [Revised: 10/07/2008] [Indexed: 05/27/2023]
Abstract
Raman-scattering measurements are used to follow the modification of the vibrational density of states in a reactive epoxy-amine mixture during isothermal polymerization. Combining them with Brillouin light and inelastic x-ray scattering measurements, we analyze the variations of the boson peak and of the Debye level while the system changes from liquid to glass upon increasing the number of covalent bonds among the constituent molecules. The shift and intensity variation of the boson peak are explained by the modification of the elastic properties throughout the reaction, and a master curve for the boson peak can therefore be obtained. Surprisingly, bond-induced modifications of the structure do not affect this master curve.
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Affiliation(s)
- S Caponi
- Dipartimento di Fisica, Università di Trento, Via Sommarive 14, I-38050 Povo (Trento), Italy
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27
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Bercu V, Martinelli M, Massa CA, Pardi LA, Leporini D. Signatures of the fast dynamics in glassy polystyrene: First evidence by high-field Electron Paramagnetic Resonance of molecular guests. J Chem Phys 2005; 123:174906. [PMID: 16375568 DOI: 10.1063/1.2085027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The reorientation of one small paramagnetic molecule (spin probe) in glassy polystyrene (PS) is studied by high-field electron paramagnetic resonance spectroscopy at two different Larmor frequencies (190 and 285 GHz). Two different regimes separated by a crossover region are evidenced. Below 180 K the rotational times are nearly temperature independent with no apparent distribution. In the temperature range of 180-220 K a large increase of the rotational mobility is observed with the widening of the distribution of correlation times which exhibits two components: (i) a deltalike, temperature-independent component representing the fraction of spin probes w which persist in the low-temperature dynamics; (ii) a strongly temperature-dependent component, to be described by a power distribution, representing the fraction of spin probes 1-w undergoing activated motion over an exponential distribution of barrier heights g(E). Above 180 K a steep decrease of w is evidenced. The shape and the width of g(E) do not differ from the reported ones for PS within the errors. For the first time the large increase of the rotational mobility of the spin probe at 180 K is ascribed to the onset of the fast dynamics detected by neutron scattering at T(f)=175+/-25 K.
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Affiliation(s)
- V Bercu
- Dipartimento di Fisica Enrico Fermi, Università di Pisa, Largo B. Pontecorvo 3, 1-56127 Pisa, Italy
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29
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Silbert LE, Liu AJ, Nagel SR. Vibrations and diverging length scales near the unjamming transition. PHYSICAL REVIEW LETTERS 2005; 95:098301. [PMID: 16197259 DOI: 10.1103/physrevlett.95.098301] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Indexed: 05/04/2023]
Abstract
We numerically study the vibrations of jammed packings of particles interacting with finite-range, repulsive potentials at zero temperature. As the packing fraction phi is lowered towards the onset of unjamming at phi(c), the density of vibrational states approaches a nonzero value in the limit of zero frequency. For phi >phi(c), there is a crossover frequency, omega* below which the density of states drops towards zero. This crossover frequency obeys power-law scaling with phi-phi(c). Characteristic length scales, determined from the dominant wave vector contributing to the eigenmode at omega*, diverge as power laws at the unjamming transition.
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30
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Branca C, Magazù S, Maisano G, Telling M. Fragility characterization by neutron scattering for pure homologous disaccharides. J Mol Struct 2005. [DOI: 10.1016/j.molstruc.2005.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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31
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Wu TM, Chang SL, Tsai KH. Mechanism for singular behavior in vibrational spectra of topologically disordered systems: short-range attractions. J Chem Phys 2005; 122:204501. [PMID: 15945746 DOI: 10.1063/1.1900726] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
At low-enough fluid densities, we have found some naive singular behavior, like the van Hove singularities in the phonon spectra of lattices, appearing in the instantaneous normal mode spectra of the Lennard-Jones (LJ) 2n-n fluids, which serve as a prototype of topologically disordered systems. The singular behavior cannot be predicted by the mean-field theory, but interpreted by the perturbed binary modes of some special pairs, called the mutual nearest neighbor pairs, at separations corresponding to the extreme binary frequencies, which are solely determined by the attractive part of the LJ 2n-n pair potential. By reducing the range of attraction in the pair potential under the conditions of the same particle diameter and well depth, the tendency for the appearance of the singular behavior shifts to higher fluid densities. From this study, we conclude that pair potential with a short-range attraction can be a mechanism to produce a counterpart of the van Hove singularity in the vibrational spectra of disordered systems without a reference lattice.
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Affiliation(s)
- Ten-Ming Wu
- Institute of Physics, National Chiao-Tung University, Hsin chu, Taiwan, Republic of China.
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32
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Affiliation(s)
- Yifu Ding
- Department of Polymer Science, University of Akron, Akron, Ohio 44325-3909
| | - A. Kisliuk
- Department of Polymer Science, University of Akron, Akron, Ohio 44325-3909
| | - A. P. Sokolov
- Department of Polymer Science, University of Akron, Akron, Ohio 44325-3909
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33
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34
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Smith GD, Borodin O, Paul W. A molecular-dynamics simulation study of dielectric relaxation in a 1,4-polybutadiene melt. J Chem Phys 2002. [DOI: 10.1063/1.1518684] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Nakamura R, Yamamoto S, Nakahara J. Broad Raman scattering and luminescence in β-carotene solution. J Chem Phys 2002. [DOI: 10.1063/1.1481060] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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36
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Surovtsev NV. Evaluation of terahertz density of vibrational states from specific-heat data: application to silica glass. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:061102. [PMID: 11736166 DOI: 10.1103/physreve.64.061102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2001] [Indexed: 05/23/2023]
Abstract
The efficiency of the Tikhonov regulation method for the specific-heat phonon spectrum inversion problem is demonstrated. The regulation method is applied to the evaluation of the density of vibrational states from the low-temperature specific heat of a silica glass. The density of states obtained is found to be in good agreement with the results of inelastic neutron scattering. The extracted density of states is used for the analysis of the Raman light-vibration coupling coefficient. It is established that the coupling coefficient increases with frequency faster than approximately nu at nu<10 cm(-1). In the frequency range above 10 cm(-1) the coupling coefficient is found to be in agreement with the results of previous investigations.
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Affiliation(s)
- N V Surovtsev
- Institute of Automation and Electrometry, Russian Academy of Sciences, pr. Ak. Koptyuga 1, Novosibirsk, 630090, Russia
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37
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Sim E, Patashinski AZ, Ratner MA. Supercooling in a two-dimensional Lennard-Jones mixture. J Chem Phys 2001. [DOI: 10.1063/1.1365082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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38
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Soles CL, Dimeo RM, Neumann DA, Kisliuk A, Sokolov AP, Liu J, Yee AF, Wu WL. Correlations of the Boson Peak with Positron Annihilation in Series of Polycarbonate Copolymers. Macromolecules 2001. [DOI: 10.1021/ma001913g] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christopher L. Soles
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Robert M. Dimeo
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Dan A. Neumann
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Alexander Kisliuk
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Alexei P. Sokolov
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Jianwei Liu
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Albert F. Yee
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
| | - Wen-li Wu
- Polymers Division, NIST, Gaithersburg, Maryland 20899-8541; Center for Neutron Research, NIST, Gaithersburg, Maryland 20899-8652; Department of Polymer Science, University of Akron, Akron, Ohio 44325-5309; and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
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39
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Kirillov SA, Kolomiyets TM. Disorder in Binary Polymer Systems near Their Critical Region Studied by Low-Frequency Raman Spectroscopy. J Phys Chem B 2001. [DOI: 10.1021/jp0016941] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sviatoslav A. Kirillov
- Foundation of Research and TechnologyHellas, Institute of Chemical Engineering and High-Temperature Chemical Processes (ICE/HT-FORTH), P.O. Box 1414, 265 00 Patras, Greece
| | - Tatiana M. Kolomiyets
- Foundation of Research and TechnologyHellas, Institute of Chemical Engineering and High-Temperature Chemical Processes (ICE/HT-FORTH), P.O. Box 1414, 265 00 Patras, Greece
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40
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Yannopoulos SN. The frequency-dependent depolarization ratio of the low-frequency Raman scattering of two inorganic systems in their glassy, supercooled, and molten states. J Chem Phys 2000. [DOI: 10.1063/1.1308109] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Masciovecchio C, Mermet A, Ruocco G, Sette F. Experimental evidence of the acousticlike character of the high frequency excitations in glasses. PHYSICAL REVIEW LETTERS 2000; 85:1266-1269. [PMID: 10991528 DOI: 10.1103/physrevlett.85.1266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2000] [Indexed: 05/23/2023]
Abstract
The dynamic structure factor S(Q,E) of glassy glycerol has been measured by inelastic x-ray scattering as a function of momentum transfer Q and at constant energy transfer E. This allows one to establish independently from specific models of S(Q,E) the following: (i) Propagating collective excitations exist in glasses at high Q. (ii) Their dispersion up to E higher than E(BP) (the boson peak energy) confirms that E(BP) is not the onset of modes localization. (iii) The observation of an almost Q independent plateau on the high Q side of the Brillouin peak supports numerical simulations on glasses, describing the vibrational eigenvectors in terms of acousticlike and "random" components.
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Affiliation(s)
- C Masciovecchio
- Sincrotrone Trieste, Area Science Park, I-34012, Trieste, Italy
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42
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Wiedersich J, Adichtchev SV, Rossler E. Spectral shape of relaxations in silica glass. PHYSICAL REVIEW LETTERS 2000; 84:2718-2721. [PMID: 11017308 DOI: 10.1103/physrevlett.84.2718] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/1999] [Indexed: 05/23/2023]
Abstract
Precise low-frequency light scattering experiments on silica glass are presented, covering a broad temperature and frequency range ( 9 GHz<nu<2 THz). The spectra show a power-law low-frequency wing of the relaxational part of the spectrum with an exponent alpha proportional to temperature in the range 30<T<200 K. A comparison of our results with those from acoustic attenuation experiments performed at different frequencies shows that this power-law behavior rather well describes relaxations in silica over 9 orders of magnitude in frequency. These findings can be explained by a model of thermally activated transitions in double well potentials.
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Affiliation(s)
- J Wiedersich
- Physikalisches Institut, Universitat Bayreuth, D-95440 Bayreuth, Germany
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Sokolov AP, Buchenau U, Richter D, Masciovecchio C, Sette F, Mermet A, Fioretto D, Ruocco G, Willner L, Frick B. Brillouin and Umklapp scattering in polybutadiene: comparison of neutron and x-ray scattering. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 60:R2464-7. [PMID: 11970177 DOI: 10.1103/physreve.60.r2464] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/1999] [Indexed: 04/18/2023]
Abstract
We report a comparison of high resolution inelastic x-ray Brillouin scattering to coherent inelastic neutron scattering for amorphous deuterated polybutadiene, done for one temperature in the glass phase and another one in the melt. The x-ray scattering proves to be by far the better technique for such a polymer within its present resolution bounds. The neutron scattering allows one to extend these measurements to a much better resolution, showing an additional quasielastic signal in the melt. The results suggest x-ray measurements at higher momentum transfer, to see whether they are complementary to neutrons.
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Affiliation(s)
- A P Sokolov
- Department of Polymer Science, University of Akron, Akron, Ohio 44325-3909, USA
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Kirillov S, Perova T, Faurskov Nielsen O, Praestgaard E, Rasmussen U, Kolomiyets T, Voyiatzis G, Anastasiadis S. Fitting the low-frequency Raman spectra to boson peak models: glycerol, triacetin and polystyrene. J Mol Struct 1999. [DOI: 10.1016/s0022-2860(98)00878-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Gapiński J, Steffen W, Patkowski A, Sokolov AP, Kisliuk A, Buchenau U, Russina M, Mezei F, Schober H. Spectrum of fast dynamics in glass forming liquids: Does the “knee” exist? J Chem Phys 1999. [DOI: 10.1063/1.477966] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Nemilov SV. The possibilities of modeling neural networks in the framework of the thermodynamics of genetically disordered systems (glasses). J Biol Phys 1998; 24:41-58. [PMID: 23345668 DOI: 10.1023/a:1005071706864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Non-spin glasses possess a number of specific features which, in structural and dynamic aspects, are close to conditions necessary for neural networks to function. In a disordered network there exists a plurality of structural parameters and a number of two-level states defined by double-well potentials. Their characteristics are specified by the conditions of glass formation, i.e. by genesis. The thermodynamic description of glass as a self-organizing system (that does not require introducing an interacting potential model) leads to an unambiguous conclusion that its frequency spectrum is predetermined by the structure, which is characterized by zero-point entropy. Glass is a natural system of oscillators which form a disordered network. In this sense, glass conforms to a known model of a disordered neural network formed by interconnected oscillators. If one assumes that in living organisms the structure of a neural network (the brain) is inherited according to a genetic mechanism, the quickness of learning and recognition of patterns, the stability of associative memory and other capabilities have to be inherited genetically. The more ordered a neural network formed by distinguishable neurons, the better its capabilities.
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Affiliation(s)
- S V Nemilov
- All-Russian Research Center, 'S. I. Vavilov State Optical Institute', Birzhevaya liniya, 12, St.-Petersburg, 199034 Russia
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