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Zografi G, Newman A, Shalaev E. Structural Features of the Glassy State and Their Impact on the Solid-State Properties of Organic Molecules in Pharmaceutical Systems. J Pharm Sci 2024:S0022-3549(24)00186-2. [PMID: 38768756 DOI: 10.1016/j.xphs.2024.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/22/2024]
Abstract
This paper reviews the structure and properties of amorphous active pharmaceutical ingredients (APIs), including small molecules and proteins, in the glassy state (below the glass transition temperature, Tg). Amorphous materials in the neat state and formulated with excipients as miscible amorphous mixtures are included, and the role of absorbed water in affecting glass structure and stability has also been considered. We defined the term "structure" to indicate the way the various molecules in a glass interact with each other and form distinctive molecular arrangements as regions or domains of varying number of molecules, molecular packing, and density. Evidence is presented to suggest that such systems generally exist as heterogeneous structures made up of high-density domains surrounded by a lower density arrangement of molecules, termed the microstructure. It has been shown that the method of preparation and the time frame for handling and storage can give rise to variable glass structures and varying physical properties. Throughout this paper, examples are given of theoretical, computer simulation, and experimental studies which focus on the nature of intermolecular interactions, the size of heterogeneous higher density domains, and the impact of such systems on the relative physical and chemical stability of pharmaceutical systems.
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Affiliation(s)
- George Zografi
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, United States
| | - Ann Newman
- Seventh Street Development Group LLC, Kure Beach, NC, United States.
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2
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Singh LP. Primary and secondary relaxation processes in poly(propylene glycol) monobutyl ether: a broadband dielectric spectroscopy investigation. Polym J 2022. [DOI: 10.1038/s41428-022-00728-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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3
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Kapourani A, Andriotis EG, Chachlioutaki K, Kontogiannopoulos KN, Klonos PA, Kyritsis A, Pavlidou E, Bikiaris DN, Fatouros DG, Barmpalexis P. High-Drug-Loading Amorphous Solid Dispersions via In Situ Thermal Cross-Linking: Unraveling the Mechanisms of Stabilization. Mol Pharm 2021; 18:4393-4414. [PMID: 34699238 DOI: 10.1021/acs.molpharmaceut.1c00563] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This article takes a step forward in understanding the mechanisms involved during the preparation and performance of cross-linked high-drug-loading (HDL) amorphous solid dispersions (ASDs). Specifically, ASDs, having 90 wt % poorly water-soluble drug indomethacin (IND), were prepared via in situ thermal cross-linking of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) and thoroughly evaluated in terms of physical stability and in vitro supersaturation. Results showed that HDL ASDs having excellent active pharmaceutical ingredient (API) amorphous stability and prolonged in vitro supersaturation were prepared by fine tuning the cross-linking procedure. Unraveling of the processes involved during ASD's formation shed light on the significant role of the cross-linking conditions (i.e., temperature and time), the physicochemical properties of the API, and the hydrolysis level of the cross-linker as key factors in modulating ASD's stability. In-depth analysis of the prepared systems revealed the (1) reduction of API's molecular motions within the cross-linked polymeric networks (through API's strong spatial confinement), (2) the structural changes in the prepared cross-linked matrices (induced by the high API drug loading), and (3) the tuning of the cross-linking density via utilization of low-hydrolyzed PVA as the major mechanisms responsible for ASD's exceptional performance. Complementary analysis by means of molecular dynamics simulations also highlighted the vital role of strong drug-polymer intermolecular interactions evolving among the ASD components. Overall, the impression of the complexity of in situ cross-linked ASDs has been reinforced with the excessive variation of parameters investigated in the current study, offering thus insights up to the submolecular level to lay the groundwork and foundations for the comprehensive assessment of a new emerging class of HDL amorphous API formulations.
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Affiliation(s)
- Afroditi Kapourani
- Department of Pharmaceutical Technology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Eleftherios G Andriotis
- Department of Pharmaceutical Technology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Konstantina Chachlioutaki
- Department of Pharmaceutical Technology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Konstantinos N Kontogiannopoulos
- Department of Pharmaceutical Technology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.,Natural Products Research Centre of Excellence-AUTH (NatPro-AUTH), Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Thessaloniki 57001, Greece
| | - Panagiotis A Klonos
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens 15780, Greece
| | - Apostolos Kyritsis
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens 15780, Greece
| | - Eleni Pavlidou
- Solid State Section, Physics Department, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Dimitrios N Bikiaris
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Dimitrios G Fatouros
- Department of Pharmaceutical Technology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Panagiotis Barmpalexis
- Department of Pharmaceutical Technology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.,Natural Products Research Centre of Excellence-AUTH (NatPro-AUTH), Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Thessaloniki 57001, Greece
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4
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Li F, Xin J, Shi Q. Diffusion-controlled and `diffusionless' crystal growth: relation between liquid dynamics and growth kinetics of griseofulvin. J Appl Crystallogr 2021. [DOI: 10.1107/s1600576720014636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Understanding how liquid dynamics govern crystallization is critical for maintaining the physical stability of amorphous pharmaceutical formulations. In the present study, griseofulvin (GSF), a classic antifungal drug, was used as the model system to investigate the correlations between crystal growth kinetics and liquid dynamics. The temperature dependence of the kinetic part of the bulk crystal growth in a supercooled liquid of GSF was weaker than that of the structural relaxation time τα and scaled as τα
−0.69. In the glassy state, GSF exhibited the glass-to-crystal (GC) growth behavior, whose growth rate was too fast to be under the control of the α-relaxation process. Moreover, from the perspective of τα, the GC growth of GSF also satisfied the general condition for GC growth to exist: D/u < 7 pm, where D is the diffusion coefficient and u the speed of crystal growth. Also compared were the fast surface crystal growth rates u
s and surface relaxation times τsurface predicted by the random first-order transition theory. Here, the surface crystal growth rate u
s of GSF exhibited a power-law dependence upon the surface structural relaxation time: u
s ∝ τsurface
−0.71, which was similar to that of the bulk growth rate and τα. These findings are important for understanding and predicting the crystallization of amorphous pharmaceutical solids both in the bulk and at the surface.
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Musiał M, Cheng S, Wojnarowska Z, Yao B, Jurkiewicz K, Paluch M. Thorough studies of tricyanomethanide-based ionic liquids - the influence of alkyl chain length of the cation. SOFT MATTER 2020; 16:9479-9487. [PMID: 32955538 DOI: 10.1039/d0sm01433h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The glassy, supercooled, and normal liquid states of the 1-alkyl-3-methylimidazolium tricyanomethanide series [CnC1im][TCM] (n = 2, 4, 6, 8, and 16) were investigated by dielectric and mechanical (rheological) experiments supplemented by X-ray diffraction. The conductivity relaxation was found to be accompanied by a pronounced secondary relaxation. However, based on ambient and high-pressure results as well as the coupling model, we assumed that the latter one can not be classified as Johari-Goldstein relaxation. Moreover, the studies on the nanoscale organization of ionic liquids indicated that 1-alkyl-3-methylimidazolium tricyanomethanide ILs begin to form nanoscale aggregates when the alkyl chain of the cation has six carbon atoms.
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Affiliation(s)
- Małgorzata Musiał
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Shinian Cheng
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Zaneta Wojnarowska
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Beibei Yao
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Karolina Jurkiewicz
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
| | - Marian Paluch
- Institute of Physics, University of Silesia in Katowice, Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
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Das R, Tah I, Karmakar S. Possible universal relation between short timeβ-relaxation and long timeα-relaxation in glass-forming liquids. J Chem Phys 2018; 149:024501. [DOI: 10.1063/1.5033555] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Rajsekhar Das
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500107, India
| | - Indrajit Tah
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500107, India
| | - Smarajit Karmakar
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500107, India
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7
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Minecka A, Kamińska E, Tarnacka M, Dzienia A, Madejczyk O, Waliłko P, Kasprzycka A, Kamiński K, Paluch M. High pressure studies on structural and secondary relaxation dynamics in silyl derivative of D-glucose. J Chem Phys 2017; 147:064502. [DOI: 10.1063/1.4989679] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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8
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Bierwirth SP, Münzner P, Knapp TA, Gainaru C, Böhmer R. Communication: Nonadditive dielectric susceptibility spectra of associating liquids. J Chem Phys 2017; 146:101101. [DOI: 10.1063/1.4978228] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- S. P. Bierwirth
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - P. Münzner
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - T. A. Knapp
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - C. Gainaru
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - R. Böhmer
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
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9
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Zografi G, Newman A. Interrelationships Between Structure and the Properties of Amorphous Solids of Pharmaceutical Interest. J Pharm Sci 2017; 106:5-27. [DOI: 10.1016/j.xphs.2016.05.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/27/2016] [Accepted: 05/03/2016] [Indexed: 10/21/2022]
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10
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Saini MK, Murthy SSN. Glass Formation in Binary Solutions of Acetaminophen with Guaifenesin and Mephenesin. J SOLUTION CHEM 2015. [DOI: 10.1007/s10953-015-0364-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Richert R. Supercooled Liquids and Glasses by Dielectric Relaxation Spectroscopy. ADVANCES IN CHEMICAL PHYSICS 2014. [DOI: 10.1002/9781118949702.ch4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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12
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Abstract
Abstract
Focusing on metallic glasses as model systems, we review the features and mechanisms of the β-relaxations, which are intrinsic and universal to supercooled liquids and glasses, and demonstrate their importance in understanding many crucial unresolved issues in glassy physics and materials science, including glass transition phenomena, mechanical properties, shear-banding dynamics and deformation mechanisms, diffusion and the breakdown of the Stokes–Einstein relation as well as crystallization and stability of glasses. We illustrate that it is an attractive prospect to incorporate these insights into the design of new glassy materials with extraordinary properties. We also outline important questions regarding the nature of β-relaxations and highlight some emerging research directions in this still-evolving field.
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Affiliation(s)
- Hai Bin Yu
- Physikalisches Institut, Universität Göttingen, D-37077 Göttingen, Germany
| | - Wei Hua Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hai Yang Bai
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Konrad Samwer
- Physikalisches Institut, Universität Göttingen, D-37077 Göttingen, Germany
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13
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Singh LP, Alba-Simionesco C, Richert R. Dynamics of glass-forming liquids. XVII. Dielectric relaxation and intermolecular association in a series of isomeric octyl alcohols. J Chem Phys 2014; 139:144503. [PMID: 24116631 DOI: 10.1063/1.4823998] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
It is well established that many mono-hydroxy alcohols show an extra relaxation process of the Debye type in addition to the signatures of primary and secondary structural relaxations, which is observed only in dielectric spectroscopy and related techniques. In order to gain further insight into the nature of this Debye peak, we study the linear and nonlinear dielectric behavior of a series of isomeric octyl alcohols and of mixtures of n-propanol with one of the octanols. These samples display systematic variations of the Debye peak intensity and concomitant changes in the Kirkwood correlation factor gK from 0.1 to 4, indicative of different equilibrium constants, K(c∕r), that characterize the populations of non-polar ring and polar open chain structures. For cases where K(c∕r) is not too far from unity, we find that a high electric field shifts K(c∕r) towards more chains, and that the accompanying change in the end-to-end vector of hydrogen-bond connected structures occurs on the Debye time scale. The results suggest that gK is correlated with the spectral separation of the Debye and primary structural peaks, as both features depend on steric hindrance of chain flexibility or bond rotation barriers and on average chain lengths. Based on the complex dynamics of supercooled mono-hydroxy alcohols with three relaxation peaks that cover many orders of magnitude in frequency, it is argued that a frequency dependent gK may be required for assessing the average orientational correlations within hydrogen-bonded structures correctly.
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Affiliation(s)
- Lokendra P Singh
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA
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14
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Naji M, Piazza F, Guimbretière G, Canizarès A, Vaills Y. Structural Relaxation Dynamics and Annealing Effects of Sodium Silicate Glass. J Phys Chem B 2013; 117:5757-64. [PMID: 23574051 DOI: 10.1021/jp401112s] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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15
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Ngai KL, Capaccioli S. Unified explanation of the anomalous dynamic properties of highly asymmetric polymer blends. J Chem Phys 2013; 138:054903. [DOI: 10.1063/1.4789585] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Broadband dielectric spectroscopy and calorimetric investigations of d-lyxose. Carbohydr Res 2011; 346:2165-72. [DOI: 10.1016/j.carres.2011.06.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/16/2011] [Accepted: 06/21/2011] [Indexed: 11/24/2022]
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17
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Capaccioli S, Ngai KL. Resolving the controversy on the glass transition temperature of water? J Chem Phys 2011; 135:104504. [DOI: 10.1063/1.3633242] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Sun M, Wang LM, Tian Y, Liu R, Ngai KL, Tan C. Component dynamics in miscible mixtures of water and methanol. J Phys Chem B 2011; 115:8242-8. [PMID: 21648447 DOI: 10.1021/jp202893v] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In binary mixtures with hydrophilic substances, water is usually the more mobile component and its relaxation time is shorter than those of the other components. An exception is the case of the mixture of 1-propanol with 45 mol % water, where the α-relaxation of water is slower than the α-relaxation of 1-propanol and even slower than the local relaxation of water confined in various spaces of nanometer size. This unusual result, so far obtained in a mixture of 1-propanol with water at a single composition, deserves confirmation by experiments in another mixture at more than one composition. Toward this goal, we have chosen mixtures of methanol with water at concentrations of water ranging from 10 to 40 mol % and investigated the dynamics of the slower water and the faster methanol components by broad-band dielectric relaxation measurements. The α-relaxation time of the water component becomes shorter with increasing content of the faster methanol component in the mixture as expected and is much shorter than in the mixture of 1-propanol with 45 mol % water. In mixtures with lower water contents of 10-20 mol %, the α-relaxation of the methanol component has a narrow frequency dispersion and no resolved Johari-Goldstein β-relaxation, indicating a low degree of intermolecular coupling or cooperativity of methanol. An increase of the content of the slower water component effectively enhances intermolecular coupling of the methanol component. Consequently, the α-relaxation of the methanol component becomes more cooperative, as evidenced by broadening of its frequency dispersion and the appearance of a resolved Johari-Goldstein β-relaxation of methanol when the water concentration is higher than 30 mol %. The observations are rationalized by application of the coupling model.
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Affiliation(s)
- Mingdao Sun
- State Key Laboratory of Metastable Materials Science and Technology and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, China
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19
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Kaminski K, Adrjanowicz K, Kaminska E, Paluch M. Probing of structural relaxation times in the glassy state of sucrose and trehalose based on dynamical properties of two secondary relaxation processes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:061502. [PMID: 21797367 DOI: 10.1103/physreve.83.061502] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Indexed: 05/31/2023]
Abstract
Time-dependent isothermal dielectric measurements were carried out deeply in the glassy state on two very important saccharides: sucrose and trehalose. In both compounds two prominent secondary relaxation processes were identified. The faster one is an inherent feature of the whole family of carbohydrates. The slower one can also be detected in oligo- and polysaccharides. It was shown earlier that the β process is the Johari-Goldstein (JG) relaxation coupled to motions of the glycosidic linkage, while the γ relaxation originates from motions of the exocyclic hydroxymethyl unit. Recently, it was shown that the JG relaxation process can be used to determine structural relaxation times in the glassy state [R. Casalini and C. M. Roland, Phys. Rev. Lett. 102, 035701 (2009)]. In this paper we present the results of an analysis of the data obtained during aging using two independent approaches. The first was proposed by Casalini and Roland, and the second one is based on the variation of the dielectric strength of the secondary relaxation process during aging [J. K. Vij and G. Power, J. Non-Cryst. Solids 357, 783 (2011)]. Surprisingly, we found that the estimated structural relaxation times in the glassy state of both saccharides are almost the same, independent of the type of secondary mode. This finding calls into question the common view that secondary modes of intramolecular origin do not provide information about the dynamics of the glassy state.
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Affiliation(s)
- K Kaminski
- Institute of Physics, Silesian University, Katowice, Poland
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20
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Wang LM, Zhao Y, Sun M, Liu R, Tian Y. Dielectric relaxation dynamics in glass-forming mixtures of propanediol isomers. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:062502. [PMID: 21230694 DOI: 10.1103/physreve.82.062502] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 09/07/2010] [Indexed: 05/30/2023]
Abstract
The relaxation dynamics of 1,2-propanediol-1,3-propanediol mixtures is studied in supercooled liquid regions across a wide composition range. The composition dependences of liquid fragility and nonexponential parameter β(KWW) are presented in the hydrogen-bonded mixtures with ideal mixing. The fragility index and glass transition temperature are shown to develop inversely with β(KWW), in analogy to the dynamic behaviors in mixtures of van der Waals liquids. Negative mixing effects on liquid fragility and β(KWW) are observed, and the strongest dependence of β(KWW on relaxation dynamics is revealed at the equimolar concentration. The glass formation in isomeric liquids is also addressed.
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Affiliation(s)
- Li-Min Wang
- State Key Laboratory of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China.
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21
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Martinez-Garcia JC, Tamarit JL, Capaccioli S, Barrio M, Veglio N, Pardo LC. Alpha-relaxation dynamics of orientanionally disordered mixed crystals composed of Cl-adamantane and CN-adamantane. J Chem Phys 2010; 132:164516. [PMID: 20441297 DOI: 10.1063/1.3397997] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The alpha-relaxation dynamics of 1-cyano-adamantane (CNA) and its mixtures with 1-chloro-adamantane (ClA) has been studied by means of broadband dielectric spectroscopy. The existence of orientationally disordered (OD) face centered cubic mixed crystals (ClA(1-X)CNA(X)) for 0.5 < or = X < or = 1 has been put in evidence by thermodynamics and structural analyses. In addition to the OD phase of CNA, mixed crystals with compositions higher than the equimolar one exhibit a freezing of the orientational degrees of freedom into a glassy state, which involves also a strong increase of the antiferroelectric order at temperatures higher than the dielectric glass transition temperature. This experimental evidence is revealed by a stairlike effect in the variation of the Kirkwood factor with the temperature as a consequence of a twin effect in the dielectric strength without any anomaly in the temperature-density curves. The characteristic relaxation times are analyzed as a function of temperature and mole fraction. By setting a common temporal origin ("isochronal origin") at tau(T(g)) = 100 s for each mole fraction, it emerges that the substitution of ClA molecules by those of CNA (diminution of X) gives rise to a slow down in the dynamics, despite that the molecular volume of ClA molecules are smaller than those of CNA. This fact goes along and is accompanied by a diminution of the lattice packing with the decrease of composition. It is also shown that the heterogeneities produced by the concentration fluctuations due to the chemical disorder are the main contribution to the non-exponential character of the alpha-relaxation peaks.
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Affiliation(s)
- J C Martinez-Garcia
- Departament de Física i Enginyeria Nuclear, Grup de Caracterització de Materials, ETSEIB, Diagonal 647, Universitat Politècnicade Catalunya, 08028 Barcelona, Spain
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22
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Martínez-García JC, Tamarit JL, Pardo LC, Barrio M, Rzoska SJ, Droz-Rzoska A. Disentangling the Secondary Relaxations in the Orientationally Disordered Mixed Crystals: Cycloheptanol + Cyclooctanol Two-Component System. J Phys Chem B 2010; 114:6099-106. [DOI: 10.1021/jp100270z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julio C. Martínez-García
- Group de Caracterització de Materials, Department de Física I Enginyeria Nuclear, ETSEIB, Diagonal 647, Universitat Politècnica de Catalunya, 08028 Barcelona, Catalonia, Spain, and Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
| | - Josep Ll. Tamarit
- Group de Caracterització de Materials, Department de Física I Enginyeria Nuclear, ETSEIB, Diagonal 647, Universitat Politècnica de Catalunya, 08028 Barcelona, Catalonia, Spain, and Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
| | - Luis C. Pardo
- Group de Caracterització de Materials, Department de Física I Enginyeria Nuclear, ETSEIB, Diagonal 647, Universitat Politècnica de Catalunya, 08028 Barcelona, Catalonia, Spain, and Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
| | - María Barrio
- Group de Caracterització de Materials, Department de Física I Enginyeria Nuclear, ETSEIB, Diagonal 647, Universitat Politècnica de Catalunya, 08028 Barcelona, Catalonia, Spain, and Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
| | - Sylwester J. Rzoska
- Group de Caracterització de Materials, Department de Física I Enginyeria Nuclear, ETSEIB, Diagonal 647, Universitat Politècnica de Catalunya, 08028 Barcelona, Catalonia, Spain, and Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
| | - Aleksandra Droz-Rzoska
- Group de Caracterització de Materials, Department de Física I Enginyeria Nuclear, ETSEIB, Diagonal 647, Universitat Politècnica de Catalunya, 08028 Barcelona, Catalonia, Spain, and Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
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23
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Wang LM, Tian Y, Liu R, Richert R. Structural Relaxation Dynamics in Binary Glass-Forming Molecular Liquids with Ideal and Complex Mixing Behavior. J Phys Chem B 2010; 114:3618-22. [DOI: 10.1021/jp912223j] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- 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 and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Yongjun Tian
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Riping Liu
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Ranko Richert
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
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24
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Shinyashiki N, Yamamoto W, Yokoyama A, Yoshinari T, Yagihara S, Kita R, Ngai KL, Capaccioli S. Glass Transitions in Aqueous Solutions of Protein (Bovine Serum Albumin). J Phys Chem B 2009; 113:14448-56. [DOI: 10.1021/jp905511w] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Naoki Shinyashiki
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
| | - Wataru Yamamoto
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
| | - Ayame Yokoyama
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
| | - Takeo Yoshinari
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
| | - Shin Yagihara
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
| | - Rio Kita
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
| | - K. L. Ngai
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
| | - Simone Capaccioli
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
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25
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Wlodarczyk P, Kaminski K, Adrjanowicz K, Wojnarowska Z, Czarnota B, Paluch M, Ziolo J, Pilch J. Identification of the slower secondary relaxation’s nature in maltose by means of theoretical and dielectric studies. J Chem Phys 2009; 131:125103. [DOI: 10.1063/1.3224856] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [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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Singh LP, Murthy SSN. Dielectric and calorimetric investigation of an unusual two-component plastic crystal: cyclohexanol-neopentylglycol. Phys Chem Chem Phys 2009; 11:5110-8. [DOI: 10.1039/b817964f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Shinyashiki N, Shinohara M, Iwata Y, Goto T, Oyama M, Suzuki S, Yamamoto W, Yagihara S, Inoue T, Oyaizu S, Yamamoto S, Ngai KL, Capaccioli S. The Glass Transition and Dielectric Secondary Relaxation of Fructose−Water Mixtures. J Phys Chem B 2008; 112:15470-7. [DOI: 10.1021/jp807038r] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- N. Shinyashiki
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - M. Shinohara
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - Y. Iwata
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - T. Goto
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - M. Oyama
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - S. Suzuki
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - W. Yamamoto
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - S. Yagihara
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - T. Inoue
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - S. Oyaizu
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - S. Yamamoto
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - K. L. Ngai
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - S. Capaccioli
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan, Research & Development Division, Nichirei Foods INC, 9, Shinminato, Mihama-ku, Chiba 261-8545, Japan, Naval Research Laboratory, Washington, D.C. 20375-5320, and Dipartimento di Fisica, Università di Pisa and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
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28
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Capaccioli S, Thayyil MS, Ngai KL. Critical Issues of Current Research on the Dynamics Leading to Glass Transition. J Phys Chem B 2008; 112:16035-49. [DOI: 10.1021/jp8057433] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- S. Capaccioli
- Dipartimento di Fisica, Università di Pisa and CNR-INFM, polylab, Largo Bruno Pontecorvo, 3, I-56127 Pisa, Italy
| | - M. Shahin Thayyil
- Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo, 3, I-56127 Pisa, Italy, and Department of Physics, University of Calicut, Kerala, India
| | - K. L. Ngai
- Naval Research Laboratory, Washington, DC 20375-5320
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29
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Heuer A. Exploring the potential energy landscape of glass-forming systems: from inherent structures via metabasins to macroscopic transport. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:373101. [PMID: 21694408 DOI: 10.1088/0953-8984/20/37/373101] [Citation(s) in RCA: 203] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In this review a systematic analysis of the potential energy landscape (PEL) of glass-forming systems is presented. Starting from the thermodynamics, the route towards the dynamics is elucidated. A key step in this endeavor is the concept of metabasins. The relevant energy scales of the PEL can be characterized. Based on the simulation results for some glass-forming systems one can formulate a relevant model system (ideal Gaussian glass-former) which can be treated analytically. The macroscopic transport can be related to the microscopic hopping processes, using either the strong relation between energy (thermodynamics) and waiting times (dynamics) or, alternatively, the concepts of the continuous-time random walk. The relation to the geometric properties of the PEL is stressed. The emergence of length scales within the PEL approach as well as the nature of finite-size effects is discussed. Furthermore, the PEL view is compared to other approaches describing the glass transition.
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Affiliation(s)
- Andreas Heuer
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Corrensstraße 30, Germany
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30
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Ngai KL, Capaccioli S, Shinyashiki N. The Protein “Glass” Transition and the Role of the Solvent. J Phys Chem B 2008; 112:3826-32. [DOI: 10.1021/jp710462e] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- K. L. Ngai
- Naval Research Laboratory, Washington, DC, 20375-5320, Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy, and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy, and Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan
| | - S. Capaccioli
- Naval Research Laboratory, Washington, DC, 20375-5320, Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy, and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy, and Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan
| | - N. Shinyashiki
- Naval Research Laboratory, Washington, DC, 20375-5320, Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy, and polyLab, CNR-INFM, Largo B. Pontecorvo 3, I-56127, Pisa, Italy, and Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan
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31
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Mierzwa M, Pawlus S, Paluch M, Kaminska E, Ngai KL. Correlation between primary and secondary Johari–Goldstein relaxations in supercooled liquids: Invariance to changes in thermodynamic conditions. J Chem Phys 2008; 128:044512. [DOI: 10.1063/1.2828496] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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32
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Kessairi K, Capaccioli S, Prevosto D, Lucchesi M, Rolla P. Relaxation dynamics intert-butylpyridine/tristyrene mixture investigated by broadband dielectric spectroscopy. J Chem Phys 2007; 127:174502. [DOI: 10.1063/1.2784190] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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33
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Capaccioli S, Ngai KL, Shinyashiki N. The Johari-Goldstein beta-relaxation of water. J Phys Chem B 2007; 111:8197-209. [PMID: 17585798 DOI: 10.1021/jp071857m] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There is a plethora of experimental data on the dynamics of water in mixtures with glycerol, ethylene glycol, ethylene glycol oligomers, poly(ethylene glycol) 400 and 600, propanol, poly(vinyl pyrrolidone), poly(vinyl methylether), and other substances. In spite of the differences in the water contents, the chemical compositions, and the glass transition temperatures Tg of these aqueous mixtures, a faster relaxation originating from the water (called the nu-process) is omnipresent, sharing the following common properties. The relaxation time tau(nu) has Arrhenius temperature dependence at temperatures below Tg of the mixture. The activation energies of tau(nu) all fall within a neighborhood of 50 kJ/mol. At the same temperature where mixtures are all in their glassy states, the values of tau(nu) of several mixtures are comparable. The Arrhenius temperature dependence of tau(nu) does not continue to higher temperatures and instead it crosses over to a stronger temperature dependence at temperatures above Tg. The dielectric relaxation strength of the nu-process, Deltaepsilon(nu)(T), has a stronger temperature dependence above Tg than below, mimicking the change of enthalpy, entropy, and volume when crossing Tg. These general property of the nu-process (except for the magnitude of the activation energy) had been found before in the secondary relaxation of the faster component in several binary nonaqueous mixtures. Other properties of the secondary relaxation in these nonaqueous mixtures have helped to identify it as the Johari-Goldstein (JG) secondary relaxation of the faster component. The similarities in properties lead us to conclude that the nu-processes in water mixtures are the JG secondary relaxations of water. The conclusion is reinforced by the processes behaving similarly to the nu-process found in 6 A thick water layer (two molecular layers) in fully hydrated Na-vermiculite clay, and in water confined in molecular sieves, silica hydrogels, and poly(2-hydroxyethyl methacrylate) hydrogels.
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Affiliation(s)
- S Capaccioli
- Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
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34
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Smith GD, Bedrov D. Relationship between the α- and β-relaxation processes in amorphous polymers: Insight from atomistic molecular dynamics simulations of 1,4-polybutadiene melts and blends. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/polb.21064] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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35
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Ngai KL. All standard theories and models of glass transition appear to be inadequate: missing some essential physics. SOFT MATTER UNDER EXOGENIC IMPACTS 2007. [DOI: 10.1007/978-1-4020-5872-1_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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36
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Bedrov D, Smith GD. A Molecular Dynamics Simulation Study of Segmental Relaxation Processes in Miscible Polymer Blends. Macromolecules 2006. [DOI: 10.1021/ma0608828] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dmitry Bedrov
- Department of Materials Science and Engineering, University of Utah, 122 S. Central Campus Dr., Rm. 304, Salt Lake City, Utah 84112
| | - Grant D. Smith
- Department of Materials Science and Engineering, University of Utah, 122 S. Central Campus Dr., Rm. 304, Salt Lake City, Utah 84112
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37
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Ngai KL, Capaccioli S, Roland CM. Comment on “A Molecular Dynamics Simulation Study of Relaxation Processes in the Dynamical Fast Component of Miscible Polymer Blends”. Macromolecules 2006. [DOI: 10.1021/ma061279s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. L. Ngai
- Naval Research Laboratory, Washington, D.C. 20375-5320; Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy; and CNR-INFM, CRS SOFT, Piazzale A. Moro 2, 00185, Roma, Italy
| | - S. Capaccioli
- Naval Research Laboratory, Washington, D.C. 20375-5320; Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy; and CNR-INFM, CRS SOFT, Piazzale A. Moro 2, 00185, Roma, Italy
| | - C. M. Roland
- Naval Research Laboratory, Washington, D.C. 20375-5320; Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy; and CNR-INFM, CRS SOFT, Piazzale A. Moro 2, 00185, Roma, Italy
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38
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Pardo LC, Lunkenheimer P, Loidl A. α and β relaxation dynamics of a fragile plastic crystal. J Chem Phys 2006; 124:124911. [PMID: 16599729 DOI: 10.1063/1.2180786] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a thorough dielectric investigation of the relaxation dynamics of plastic crystalline Freon112, which exhibits freezing of the orientational degrees of freedom into a glassy crystal below 90 K. Among other plastic crystals, Freon112 stands out by being relatively fragile within Angell's [Relaxations in Complex Systems, edited by K. L. Ngai and G. B. Wright (NRL, Washington, DC, 1985), p. 3] classification scheme and by showing an unusually strong beta relaxation. Comparing the results to those on Freon112a, having only a single molecular conformation, points to the importance of the presence of two molecular conformations in Freon112 for the explanation of its unusual properties.
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Affiliation(s)
- L C Pardo
- Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg, Germany.
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Pawlus S, Paluch M, Kaminska E, Ngai KL. Anomalous Narrowing of the Structural Relaxation Dispersion of Tris(dimethylsiloxy)phenylsilane at Elevated Pressures. J Phys Chem B 2006; 110:7678-81. [PMID: 16610860 DOI: 10.1021/jp056376m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Broadband dielectric relaxation measurements of tris(dimethylsiloxy)phenylsilane were made at ambient pressure and at elevated pressures. The data show an anomalous behavior not previously seen in any other glass-formers; namely, the structural alpha-relaxation loss peak narrows with increasing pressure and temperature at constant peak frequency. Interpreted by the coupling model, the effect is due to reduction of intermolecular coupling at elevated pressures. This interpretation has support from the observed decrease of the separation between the alpha-relaxation and the Johari-Goldstein secondary relaxation, as well as the smaller steepness or "fragility" index m of the data obtained at 1.7 GPa than at ambient pressure.
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Affiliation(s)
- Sebastian Pawlus
- Institute of Physics, Silesian University, ul. Uniwersytecka 4, 40-007 Katowice, Poland
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