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Röwekamp L, Moch K, Gainaru C, Böhmer R. Predicting Dielectric and Shear-Rheology Properties of Glass-Forming Pharmaceutical Liquids from Each Other: Applications and Limitations. Mol Pharm 2022; 19:1586-1597. [PMID: 35405077 DOI: 10.1021/acs.molpharmaceut.2c00077] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acetaminophen, nicotine, and lidocaine hydrochloride were investigated in their deeply supercooled liquid states using oscillatory shear rheology. The mechanical spectra of these drugs are presented in modulus, compliance, as well as fluidity formats. Their frequency profiles can be described via models adapted from the field of charge transport. Inspired by the success of this approach, the Barton-Nakajima-Namikawa relation, best known from the same field, was also tested. When adapted to rheology, this approach interrelates static and dynamic characteristics of viscous flow and was found to work excellently. The temperature dependence of the characteristic shear frequencies was checked against the shoving model, which relates them to the temperature-dependent instantaneous shear modulus and acceptable agreement was found. Combined with shear mechanical literature data on ibuprofen and indomethacin, a modified version of the phenomenological model by Gemant, DiMarzio, and Bishop (GDB) was employed to successfully predict the shape and amplitude of the dielectric spectra for all studied liquids, except for lidocaine hydrochloride. For the latter, the modified GDB model is suggested to aid in mapping out the reorientational part of the dielectric response, while the experimental results are strongly superimposed by ionic conduction phenomena. The reverse transformation, the calculation of rheological spectra based on dielectric ones, is also successfully demonstrated. For the example of acetyl salicylic acid, it is shown how dielectric spectra can be used to even predict rheological ones. The limits of the central parameter governing these mutual transformations, the electroviscoelastic material constant, and indications for its correlation with the dielectric relaxation strength are discussed. For pharmaceuticals characterized by a strong dynamical decoupling of the electrical from the mechanical degrees of freedom, the modified GDB model is not expected to be applicable.
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Affiliation(s)
- Lara Röwekamp
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - Kevin Moch
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - Catalin Gainaru
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Roland Böhmer
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany
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2
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Brás A, Arizaga A, Agirre U, Dorau M, Houston J, Radulescu A, Kruteva M, Pyckhout-Hintzen W, Schmidt AM. Chain-End Effects on Supramolecular Poly(ethylene glycol) Polymers. Polymers (Basel) 2021; 13:2235. [PMID: 34300992 PMCID: PMC8309292 DOI: 10.3390/polym13142235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 06/30/2021] [Accepted: 06/30/2021] [Indexed: 11/25/2022] Open
Abstract
In this work we present a fundamental analysis based on small-angle scattering, linear rheology and differential scanning calorimetry (DSC) experiments of the role of different hydrogen bonding (H-bonding) types on the structure and dynamics of chain-end modified poly(ethylene glycol) (PEG) in bulk. As such bifunctional PEG with a molar mass below the entanglement mass Me is symmetrically end-functionalized with three different hydrogen bonding (H-bonding) groups: thymine-1-acetic acid (thy), diamino-triazine (dat) and 2-ureido-4[1H]-pyrimidinone (upy). A linear block copolymer structure and a Newtonian-like dynamics is observed for PEG-thy/dat while results for PEG-upy structure and dynamics reveal a sphere and a network-like behavior, respectively. These observations are concomitant with an increase of the Flory-Huggins interaction parameter from PEG-thy/dat to PEG-upy that is used to quantify the difference between the H-bonding types. The upy association into spherical clusters is established by the Percus-Yevick approximation that models the inter-particle structure factor for PEG-upy. Moreover, the viscosity study reveals for PEG-upy a shear thickening behavior interpreted in terms of the free path model and related to the time for PEG-upy to dissociate from the upy clusters, seen as virtual crosslinks of the formed network. Moreover, a second relaxation time of different nature is also obtained from the complex shear modulus measurements of PEG-upy by the inverse of the angular frequency where G' and G'' crosses from the network-like to glass-like transition relaxation time, which is related to the segmental friction of PEG-upy polymeric network strands. In fact, not only do PEG-thy/dat and PEG-upy have different viscoelastic properties, but the relaxation times found for PEG-upy are much slower than the ones for PEG-thy/dat. However, the activation energy related to the association dynamics is very similar for both PEG-thy/dat and PEG-upy. Concerning the segmental dynamics, the glass transition temperature obtained from both rheological and calorimetric analysis is similar and increases for PEG-upy while for PEG-thy/dat is almost independent of association behavior. Our results show how supramolecular PEG properties vary by modifying the H-bonding association type and changing the molecular Flory-Huggins interaction parameter, which can be further explored for possible applications.
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Affiliation(s)
- Ana Brás
- Institute of Physical Chemistry, University of Cologne, 50939 Cologne, Germany; (A.A.); (U.A.); (M.D.); (A.M.S.)
| | - Ana Arizaga
- Institute of Physical Chemistry, University of Cologne, 50939 Cologne, Germany; (A.A.); (U.A.); (M.D.); (A.M.S.)
| | - Uxue Agirre
- Institute of Physical Chemistry, University of Cologne, 50939 Cologne, Germany; (A.A.); (U.A.); (M.D.); (A.M.S.)
| | - Marie Dorau
- Institute of Physical Chemistry, University of Cologne, 50939 Cologne, Germany; (A.A.); (U.A.); (M.D.); (A.M.S.)
| | - Judith Houston
- Jülich Centre for Neutron Science (JCNS-1) at Heinz Maier Leibnitz-Zentrum (MLZ), Forschungszentrum Jülich GmbH, 85748 Garching, Germany; (J.H.); (A.R.)
| | - Aurel Radulescu
- Jülich Centre for Neutron Science (JCNS-1) at Heinz Maier Leibnitz-Zentrum (MLZ), Forschungszentrum Jülich GmbH, 85748 Garching, Germany; (J.H.); (A.R.)
| | - Margarita Kruteva
- Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany; (M.K.); (W.P.-H.)
| | - Wim Pyckhout-Hintzen
- Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany; (M.K.); (W.P.-H.)
| | - Annette M. Schmidt
- Institute of Physical Chemistry, University of Cologne, 50939 Cologne, Germany; (A.A.); (U.A.); (M.D.); (A.M.S.)
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Yu L, Qian D, Marina S, Nugroho FAA, Sharma A, Hultmark S, Hofmann AI, Kroon R, Benduhn J, Smilgies DM, Vandewal K, Andersson MR, Langhammer C, Martín J, Gao F, Müller C. Diffusion-Limited Crystallization: A Rationale for the Thermal Stability of Non-Fullerene Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2019; 11:21766-21774. [PMID: 31185565 DOI: 10.1021/acsami.9b04554] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Organic solar cells are thought to suffer from poor thermal stability of the active layer nanostructure, a common belief that is based on the extensive work that has been carried out on fullerene-based systems. We show that a widely studied non-fullerene acceptor, the indacenodithienothiophene-based acceptor ITIC, crystallizes in a profoundly different way as compared to fullerenes. Although fullerenes are frozen below the glass-transition temperature Tg of the photovoltaic blend, ITIC can undergo a glass-crystal transition considerably below its high Tg of ∼180 °C. Nanoscopic crystallites of a low-temperature polymorph are able to form through a diffusion-limited crystallization process. The resulting fine-grained nanostructure does not evolve further with time and hence is characterized by a high degree of thermal stability. Instead, above Tg, the low temperature polymorph melts, and micrometer-sized crystals of a high-temperature polymorph develop, enabled by more rapid diffusion and hence long-range mass transport. This leads to the same detrimental decrease in photovoltaic performance that is known to occur also in the case of fullerene-based blends. Besides explaining the superior thermal stability of non-fullerene blends at relatively high temperatures, our work introduces a new rationale for the design of bulk heterojunctions that is not based on the selection of high- Tg materials per se but diffusion-limited crystallization. The planar structure of ITIC and potentially other non-fullerene acceptors readily facilitates the desired glass-crystal transition, which constitutes a significant advantage over fullerenes, and may pave the way for truly stable organic solar cells.
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Affiliation(s)
- Liyang Yu
- College of Chemistry , Sichuan University , Chengdu 610064 , P. R. China
| | - Deping Qian
- Department of Physics, Chemistry and Biology (IFM) , Linköping University , SE-581 83 Linköping , Sweden
| | - Sara Marina
- POLYMAT and Polymer Science and Technology Department, Faculty of Chemistry , University of the Basque Country UPV/EHU , Paseo Manuel de Lardizabal 3 , 20018 Donostia-San Sebastián , Spain
| | | | - Anirudh Sharma
- Flinders Institute for Nanoscale Science and Technology , Flinders University , Sturt Road , Bedford Park, Adelaide , SA 5042 , Australia
- Laboratoire de Chimie des Polymères Organiques (LCPO) , University of Bordeaux, UMR 5629 , B8 Allée Geoffroy Saint Hilaire , 33615 Pessac Cedex , France
| | | | | | | | - Johannes Benduhn
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics , Technische Universität Dresden , Nöthnitzer Straße 61 , 01187 Dresden , Germany
| | - Detlef-M Smilgies
- Cornell High Energy Synchrotron Source (CHESS) , Ithaca , New York 14850 , United States
| | - Koen Vandewal
- Institute for Materials Research (IMO-IMOMEC) , Hasselt University , Wetenschapspark 1 , 3590 Diepenbeek , Belgium
| | - Mats R Andersson
- Flinders Institute for Nanoscale Science and Technology , Flinders University , Sturt Road , Bedford Park, Adelaide , SA 5042 , Australia
| | | | - Jaime Martín
- POLYMAT and Polymer Science and Technology Department, Faculty of Chemistry , University of the Basque Country UPV/EHU , Paseo Manuel de Lardizabal 3 , 20018 Donostia-San Sebastián , Spain
- Ikerbasque, Basque Foundation for Science , E-48011 Bilbao , Spain
| | - Feng Gao
- Department of Physics, Chemistry and Biology (IFM) , Linköping University , SE-581 83 Linköping , Sweden
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Policianova O, Brus J, Hruby M, Urbanova M, Zhigunov A, Kredatusova J, Kobera L. Structural diversity of solid dispersions of acetylsalicylic acid as seen by solid-state NMR. Mol Pharm 2014; 11:516-30. [PMID: 24417442 DOI: 10.1021/mp400495h] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Solid dispersions of active pharmaceutical ingredients are of increasing interest due to their versatile use. In the present study polyvinylpyrrolidone (PVP), poly[N-(2-hydroxypropyl)-metacrylamide] (pHPMA), poly(2-ethyl-2-oxazoline) (PEOx), and polyethylene glycol (PEG), each in three Mw, were used to demonstrate structural diversity of solid dispersions. Acetylsalicylic acid (ASA) was used as a model drug. Four distinct types of the solid dispersions of ASA were created using a freeze-drying method: (i) crystalline solid dispersions containing nanocrystalline ASA in a crystalline PEG matrix; (ii) amorphous glass suspensions with large ASA crystallites embedded in amorphous pHPMA; (iii) solid solutions with molecularly dispersed ASA in rigid amorphous PVP; and (iv) nanoheterogeneous solid solutions/suspensions containing nanosized ASA clusters dispersed in a semiflexible matrix of PEOx. The obtained structural data confirmed that the type of solid dispersion can be primarily controlled by the chemical constitutions of the applied polymers, while the molecular weight of the polymers had no detectable impact. The molecular structure of the prepared dispersions was characterized using solid-state NMR, wide-angle X-ray scattering (WAXS), and differential scanning calorimetry (DSC). By applying various (1)H-(13)C and (1)H-(1)H correlation experiments combined with T1((1)H) and T1ρ((1)H) relaxation data, the extent of the molecular mixing was determined over a wide range of distances, from intimate intermolecular contacts (0.1-0.5 nm) up to the phase-separated nanodomains reaching ca. 500 nm. Hydrogen-bond interactions between ASA and polymers were probed by the analysis of (13)C and (15)N CP/MAS NMR spectra combined with the measurements of (1)H-(15)N dipolar profiles. Overall potentialities and limitations of individual experimental techniques were thoroughly evaluated.
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Affiliation(s)
- Olivia Policianova
- Institute of Macromolecular Chemistry , Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Praha 6, Czech Republic
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5
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Shibata T, Takayama H, Kim TH, Kojima S. Acoustic and thermal anomalies in a liquid–glass transition of racemic S(+)–R(−) ketoprofen. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Rodrigues AC, Viciosa MT, Danède F, Affouard F, Correia NT. Molecular Mobility of Amorphous S-Flurbiprofen: A Dielectric Relaxation Spectroscopy Approach. Mol Pharm 2013; 11:112-30. [DOI: 10.1021/mp4002188] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. C. Rodrigues
- REQUIMTE/CQFB, Departamento de Química, Faculdade
de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - M. T. Viciosa
- CQFM − Centro
de Química-Física Molecular and IN − Institute
of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal
| | - F. Danède
- Unité Matériaux et Transformation (UMET), UMR CNRS
8207, UFR de Physique, BAT P5, Université Lille 1, 59655 Villeneuve d’Ascq, France
| | - F. Affouard
- Unité Matériaux et Transformation (UMET), UMR CNRS
8207, UFR de Physique, BAT P5, Université Lille 1, 59655 Villeneuve d’Ascq, France
| | - N. T. Correia
- REQUIMTE/CQFB, Departamento de Química, Faculdade
de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
- Unité Matériaux et Transformation (UMET), UMR CNRS
8207, UFR de Physique, BAT P5, Université Lille 1, 59655 Villeneuve d’Ascq, France
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7
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Abstract
Banded spherulites of aspirin have been crystallized from the melt in the presence of salicylic acid either generated from aspirin decomposition or added deliberately (2.6-35.9 mol %). Scanning electron microscopy, X-ray diffraction analysis, and optical polarimetry show that the spherulites are composed of helicoidal crystallites twisted along the <010> growth directions. Mueller matrix imaging reveals radial oscillations in not only linear birefringence, but also circular birefringence, whose origin is explained through slight (∼1.3°) but systematic splaying of individual lamellae in the film. Strain associated with the replacement of aspirin molecules by salicylic acid molecules in the crystal structure is computed to be large enough to work as the driving force for the twisting of crystallites.
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Affiliation(s)
- Xiaoyan Cui
- Department of Chemistry, New York University, 100 Washington Square East, Silver Center, Room 1001, New York, New York 10003, United States
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8
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Kwon HJ, Kim TH, Ko JH, Hwang YH. Relaxation phenomena in supercooled liquid and glassy acetaminophen studied by dielectric, photon correlation and Brillouin light scattering spectroscopies. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.11.072] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Zhang Y, Tyagi M, Mamontov E, Chen SH. Quasi-elastic neutron scattering studies of the slow dynamics of supercooled and glassy aspirin. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:064112. [PMID: 22277723 DOI: 10.1088/0953-8984/24/6/064112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Aspirin, also known as acetylsalicylic acid (ASA), is not only a wonderful drug, but also a good glass former. Therefore, it serves as an important molecular system to study the near-arrest and arrested phenomena. In this paper, a high-resolution quasi-elastic neutron scattering (QENS) technique is used to investigate the slow dynamics of supercooled liquid and glassy aspirin from 410 down to 350 K. The measured QENS spectra can be analyzed with a stretched exponential model. We find that (i) the stretched exponent β(Q) is independent of the wavevector transfer Q in the measured Q range and (ii) the structural relaxation time τ(Q) follows a power-law dependence on Q. Consequently, the Q-independent structural relaxation time τ(0) can be extracted for each temperature to characterize the slow dynamics of aspirin. The temperature dependence of τ(0) can be fitted with the mode-coupling power law, the Vogel-Fulcher-Tammann equation and a universal equation for fragile glass forming liquids recently proposed by Tokuyama in the measured temperature range. The calculated dynamic response function χ(T)(Q, t) using the experimentally determined self-intermediate scattering function of the hydrogen atoms of aspirin shows direct evidence of the enhanced dynamic fluctuations as the aspirin is increasingly supercooled, in agreement with the fixed-time mean squared displacement ⟨x(2)⟩ and the non-Gaussian parameter α(2) extracted from the elastic scattering.
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Affiliation(s)
- Yang Zhang
- Neutron Scattering Science Division and Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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10
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Elastic properties of aspirin in its crystalline and glassy phases studied by micro-Brillouin scattering. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.09.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Brás AR, Noronha JP, Antunes AMM, Cardoso MM, Schönhals A, Affouard F, Dionísio M, Correia NT. Molecular Motions in Amorphous Ibuprofen As Studied by Broadband Dielectric Spectroscopy. J Phys Chem B 2008; 112:11087-99. [DOI: 10.1021/jp8040428] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ana R. Brás
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - João P. Noronha
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Alexandra M. M. Antunes
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Maria M. Cardoso
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Andreas Schönhals
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Frédéric Affouard
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Madalena Dionísio
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Natália T. Correia
- Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal, Federal Institute of Materials Research and Testing (BAM), Unter den Eichen 87, D-12205 Berlin, Germany, and Laboratoire de Dynamique et Structure des Matériaux Moléculaires, UMR CNRS 8024, UFR de Physique, BAT P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
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Nowaczyk A, Geil B, Hinze G, Böhmer R. Correlation of primary relaxations and high-frequency modes in supercooled liquids. II. Evidence from spin-lattice relaxation weighted stimulated-echo spectroscopy. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 74:041505. [PMID: 17155063 DOI: 10.1103/physreve.74.041505] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Indexed: 05/12/2023]
Abstract
Using spin-lattice relaxation weighted stimulated-echo spectroscopy, we report evidence for a correlation of the primary and secondary relaxation times. The experiments are performed using deuteron nuclear magnetic resonance somewhat above the calorimetric glass-transition of ortho-terphenyl, D-sorbitol, and cresolphthalein-dimethylether. The data analysis is based on the procedure outlined in the accompanying theoretical paper [B. Geil, G. Diezemann, and R. Böhmer, Phys. Rev. E 74, 041504 (2006)]. Direct experimental evidence for a modified spin-lattice relaxation is obtained from measurements on a methyl deuterated acetyl salicylic acid glass. The limitations of the present experimental method are discussed.
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Affiliation(s)
- A Nowaczyk
- Experimentelle Physik III and Interdisziplinäres Zentrum für Magnetische Resonanz, Universität Dortmund, 44221 Dortmund, Germany
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