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Ageeva TA, Bush AA, Golubev DV, Gorshkova AS, Kamentsev KE, Koifman OI, Rumyantseva VD, Sigov AS, Fomichev VV. Porphyrin metal complexes with a large dipole moment. J Organomet Chem 2020. [DOI: 10.1016/j.jorganchem.2020.121355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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2
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Ni Y, Song H, Wilcox DA, Medvedev GA, Boudouris BW, Caruthers JM. Rethinking the Analysis of the Linear Viscoelastic Behavior of an Epoxy Polymer near and above the Glass Transition. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yelin Ni
- Davidson School of Chemical Engineering; Forney Hall of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907-2100, United States
| | - Hosup Song
- Davidson School of Chemical Engineering; Forney Hall of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907-2100, United States
| | - Daniel A. Wilcox
- Davidson School of Chemical Engineering; Forney Hall of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907-2100, United States
| | - Grigori A. Medvedev
- Davidson School of Chemical Engineering; Forney Hall of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907-2100, United States
| | - Bryan W. Boudouris
- Davidson School of Chemical Engineering; Forney Hall of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907-2100, United States
| | - James M. Caruthers
- Davidson School of Chemical Engineering; Forney Hall of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907-2100, United States
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Physical Meanings of Fractal Behaviors of Water in Aqueous and Biological Systems with Open-Ended Coaxial Electrodes. SENSORS 2019; 19:s19112606. [PMID: 31181722 PMCID: PMC6604069 DOI: 10.3390/s19112606] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/01/2022]
Abstract
The dynamics of a hydrogen bonding network (HBN) relating to macroscopic properties of hydrogen bonding liquids were observed as a significant relaxation process by dielectric spectroscopy measurements. In the cases of water and water rich mixtures including biological systems, a GHz frequency relaxation process appearing at around 20 GHz with the relaxation time of 8.2 ps is generally observed at 25 °C. The GHz frequency process can be explained as a rate process of exchanges in hydrogen bond (HB) and the rate becomes higher with increasing HB density. In the present work, this study analyzed the GHz frequency process observed by suitable open-ended coaxial electrodes, and physical meanings of the fractal nature of water structures were clarified in various aqueous systems. Dynamic behaviors of HBN were characterized by a combination of the average relaxation time and the distribution of the relaxation time. This fractal analysis offered an available approach to both solution and dispersion systems with characterization of the aggregation or dispersion state of water molecules. In the case of polymer-water mixtures, the HBN and polymer networks penetrate each other, however, the HBN were segmented and isolated more by dispersed and aggregated particles in the case of dispersion systems. These HBN fragments were characterized by smaller values of the fractal dimension obtained from the fractal analysis. Some examples of actual usages suggest that the fractal analysis is now one of the most effective tools to understand the molecular mechanism of HBN in aqueous complex materials including biological systems.
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Medvedev GA, Caruthers JM. A Quantitative Model of Super-Arrhenian Behavior in Glass-Forming Polymers. Macromolecules 2019. [DOI: 10.1021/acs.macromol.8b02413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Grigori A. Medvedev
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - James M. Caruthers
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
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5
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Tahalyani J, Datar S, Balasubramanian K. Investigation of dielectric properties of free standing electrospun nonwoven mat. J Appl Polym Sci 2017. [DOI: 10.1002/app.46121] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Jitendra Tahalyani
- Department of Electronics and Communication Engineering; JK Laxmipat University; Jaipur 302026 India
| | - Suwarna Datar
- Department of Applied Physics; Defence Institute of Advanced Technology; Girinagar 411025 India
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Evidence of both unusual dielectric mode at low frequencies and the co-existence of antiferroelectric, ferroelectric and paraelectric phases in a novel antiferroelectric liquid crystals mixture. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.09.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Charge carrier relaxation studies in poly (3, 4-ethylenedioxythiophene) nanofibers. JOURNAL OF POLYMER RESEARCH 2015. [DOI: 10.1007/s10965-015-0768-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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8
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Consolati G, Quasso F. Polarization of positronium in amorphous polar polymers: a case study. J Chem Phys 2013; 139:204901. [PMID: 24289373 DOI: 10.1063/1.4832321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The features of positronium in an amorphous copolymer (polyvinyl acetate-crotonic acid) in a range of temperatures including the glass transition were investigated by means of positron annihilation lifetime spectroscopy. In particular, para-positronium lifetime was found to be longer than in a vacuum and to decrease with the temperature. This was attributed to the electron density at the positron (contact density), which is lower than in vacuo due to the presence of polar groups in the copolymer. A three quantum yield experiment confirmed the lifetime results.
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Affiliation(s)
- G Consolati
- Department of Aerospace Science and Technology, Politecnico di Milano, via La Masa, 34, Milano 20156, Italy
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Wu X, Zhu Z. Dynamic Crossover of α′ Relaxation in Poly(vinyl acetate) above Glass Transition via Mechanical Spectroscopy. J Phys Chem B 2009; 113:11147-52. [DOI: 10.1021/jp903523x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xuebang Wu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei, Anhui, P. R. China
| | - Zhengang Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei, Anhui, P. R. China
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Tyagi M, Alegría A, Colmenero J. Broadband dielectric study of oligomer of poly(vinyl acetate): a detailed comparison of dynamics with its polymer analog. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:061805. [PMID: 17677292 DOI: 10.1103/physreve.75.061805] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 02/27/2007] [Indexed: 05/16/2023]
Abstract
We have studied the dynamics of a trimer of vinyl acetate (3VAc) using broadband dielectric spectroscopy over a wide temperature range to cover its primary and secondary relaxations. The dielectric spectra for the primary process over the entire temperature range have been described in terms of the Kohlraush-Williams-Watts approach [Williams and Watts, Trans. Faraday Soc. 66, 80 (1970)]. The dielectric relaxation is found to show a characteristic crossover in the dynamics at 261 K through the temperature dependence of different dielectric parameters, viz., the relaxation time, shape parameter, and dielectric strength. Unlike in the polymer counterpart, this crossover temperature has been found to be different from the apparent merging temperature of the primary and secondary processes. Moreover, a direct comparison between the shape parameters in the case of 3VAc and poly(vinyl acetate) (PVAc) reflected a near absence of chain connectivity effects on the relaxation shape at the high-temperature side, which is interpreted as the decoupling of side group (containing the dipolar entity) motions from the main chain in the case of PVAc. A secondary relaxation for 3VAc was observed below its glass transition temperature, which is found to show the same activation energy as the beta process in PVAc, for which new measurements have been made. However, their shapes showed different temperature dependences, which are discussed in terms of the molecular structure.
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Affiliation(s)
- Madhusudan Tyagi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastian, Spain.
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Sudo S, Shimomura M, Kanari K, Shinyashiki N, Yagihara S. Broadband dielectric study of the glass transition in poly(ethyleneglycol)-water mixture. J Chem Phys 2006; 124:044901. [PMID: 16460206 DOI: 10.1063/1.2149860] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We performed broadband dielectric measurements of a polyethyleneglycol-water mixture in the frequency range between 10 GHz and 1 microHz and the temperature range between 300 and 133 K. One relaxation process is observed throughout the whole temperature range. The temperature dependence of the relaxation time clearly obeys the Vogel-Fulcher law above 183 K, and the Arrhenius law below 183 K. This observed relaxation process is the secondary process, and the primary process related to the glass transition is masked by the low-frequency ionic contribution below 183 K. The glass transition concerned with the masked primary process leads to the Vogel-Fulcher to Arrhenius transition of the secondary process.
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Affiliation(s)
- S Sudo
- Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan
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Tyagi M, Alegría A, Colmenero J. Heterogeneous dynamics of poly(vinyl acetate) far above Tg: A combined study by dielectric spectroscopy and quasielastic neutron scattering. J Chem Phys 2005; 122:244909. [PMID: 16035818 DOI: 10.1063/1.1931664] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have investigated the dynamics of poly(vinly acetate) using broadband dielectric spectroscopy (DS) covering over 14 decades in frequency up to 20 GHz and high-resolution quasielastic neutron-scattering (QENS) technique. The dielectric results have been interpreted in terms of the phenomenological Kohlrausch-Williams-Watts [G. Williams and D. C. Watts, Trans. Faraday Soc. 66, 80 (1970); F. Alvarez, A. Alegria, and J. Colmenero, Phys. Rev. B 47, 125 (1993)] description. Because of the wide frequency range covered by DS, it provides a precise determination of dynamics over a wide temperature range and it revealed a crossover in polymer dynamics at 387 K through different dielectric parameters, viz., characteristic times, asymmetric shape parameter, and dielectric strength. Moreover, shape parameter is found to be higher in comparison to other typical polymeric systems. The characteristic relaxation times observed by QENS displayed an anomalous dependence of momentum transfer, indicating the possible existence of heterogeneities in the system even at the high temperatures. In addition, spin-lattice relaxation times, T(1), were found to be decoupled from dielectric characteristic times. Based on these results, a model was proposed to account for heterogeneities where we consider coexistence of different regions with standard polymeric behavior but with different characteristic times, leading to a distribution of relaxation times. The model is found to account for the anomalous behavior and an inherent shape parameter is found to account for the shape of alpha relaxation. This model is also found to predict the T variation of T(1) characteristic time scales at all temperatures. The origin of the heterogeneous domains is believed to lie in the microstructure of polymer chains.
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Affiliation(s)
- Madhusudan Tyagi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, San Sebastian, Spain.
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Martins T, Yamaki S, Prado E, Atvars T. Broadening of the fluorescence spectra of hydrocarbons in ethylene-vinyl acetate copolymers and the dynamics of the glass transition. J Photochem Photobiol A Chem 2003. [DOI: 10.1016/s1010-6030(02)00401-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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14
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Yamaki S, Prado E, Atvars T. Phase transitions and relaxation processes in ethylene-vinyl acetate copolymers probed by fluorescence spectroscopy. Eur Polym J 2002. [DOI: 10.1016/s0014-3057(02)00067-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Development of cooperativity in the local segmental dynamics of poly(vinylacetate): synergy of thermodynamics and intermolecular coupling. POLYMER 2002. [DOI: 10.1016/s1089-3156(01)00011-3] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Kalinovskaya OE, Vij JK. Nonexponential dielectric relaxation dynamics in supercooled liquid and glassy states of isoamyl bromide and 2-methylpentane mixtures. J Chem Phys 2001. [DOI: 10.1063/1.1338511] [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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Esch M, Sukhorukov VL, Kürschner M, Zimmermann U. Dielectric properties of alginate beads and bound water relaxation studied by electrorotation. Biopolymers 1999; 50:227-37. [PMID: 10397786 DOI: 10.1002/(sici)1097-0282(199909)50:3<227::aid-bip1>3.0.co;2-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The electrical and dielectric properties of Ba2+ and Ca2+ cross-linked alginate hydrogel beads were studied by means of single-particle electrorotation. The use of microstructured electrodes allowed the measurements to be performed over a wide range of medium conductivity from about 5 mS/m to 1 S/m. Within a conductivity range, the beads exhibited measurable electrorotation response at frequencies above 0.2 MHz with two well-resolved co- and antifield peaks. With increasing medium conductivity, both peaks shifted toward higher frequency and their magnitudes decreased greatly. The results were analyzed using various dielectric models that consider the beads as homogeneous spheres with conductive loss and allow the complex rotational behavior of beads to be explained in terms of conductivity and permittivity of the hydrogel. The rotation spectra could be fitted very accurately by assuming (a) a linear relationship between the internal hydrogel conductivity and the medium conductivity, and (b) a broad internal dispersion of the hydrogel centered between 20 and 40 MHz. We attribute this dispersion to the relaxation of water bound to the polysaccharide matrix of the beads. The dielectric characterization of alginate hydrogels is of enormous interest for biotechnology and medicine, where alginate beads are widely used for immobilization of cells and enzymes, for drug delivery, and as microcarriers for cell cultivation.
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Affiliation(s)
- M Esch
- Lehrstuhl für Biotechnologie der Universität Würzburg, Biozentrum, Am Hubland, D97074 Würzburg, Germany
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Dias AB, Correia NT, Moura-Ramos JJ, Fernandes AC. Molecular motions in poly(vinyl acetate) revisited. A thermally stimulated current study. POLYM INT 1994. [DOI: 10.1002/pi.1994.210330309] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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Dias AB, Ramos JJ, Williams G. The low temperature relaxation mechanisms in poly(vinyl acetate): a thermally stimulated currents study. POLYMER 1994. [DOI: 10.1016/0032-3861(94)90020-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Dionísio MS, Moura-Ramos JJ, Williams G. Molecular motions in poly(vinyl acetate) and in poly(vinyl acetate)p-nitroaniline mixtures. POLYMER 1993. [DOI: 10.1016/0032-3861(93)90674-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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22
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Shinyashiki N, Asaka N, Mashimo S, Yagihara S. Dielectric study on dynamics of water in polymer matrix using a frequency range 106–1010 Hz. J Chem Phys 1990. [DOI: 10.1063/1.459526] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.8] [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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Murthy SSN. Comment on ‘‘The dielectric relaxation studies on poly(vinyl acetate)’’. J Chem Phys 1990. [DOI: 10.1063/1.457966] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mashimo S, Shioya Y, Nozaki R, Yagihara S. Real-time dielectric relaxation in glassy polyvinylacetate. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 37:8471-8474. [PMID: 9944195 DOI: 10.1103/physrevb.37.8471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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25
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Nozaki R, Mashimo S. Dielectric relaxation measurements of poly(vinyl acetate) in glassy state in the frequency range 10−6–106 Hz. J Chem Phys 1987. [DOI: 10.1063/1.453156] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.5] [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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Rendell RW, Ngai KL, Mashimo S. Coupling model interpretation of dielectric relaxation of poly(vinyl acetate) near Tg. J Chem Phys 1987. [DOI: 10.1063/1.453117] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Dielectric investigation of the glass relaxation in poly(vinyl acetate) and poly(vinyl chloride) under high hydrostatic pressure. Colloid Polym Sci 1985. [DOI: 10.1007/bf01469623] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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28
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Yagihara S, Nozaki R, Takeishi S, Mashimo S. Evaluation of dielectric permittivity by dc transient current. J Chem Phys 1983. [DOI: 10.1063/1.446049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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