Glass transition of polymer-molecular liquid mixtures studied by broadband dielectric spectroscopy
| Project/Area Number |
15540396
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics/Chemical physics
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| Research Institution | Tokai University |
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Principal Investigator |
SHINYASHIKI Naoki Tokai University, School of Science, Associate Professor, 理学部, 助教授 (00266363)
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| Co-Investigator(Kenkyū-buntansha) |
YAGIHARA Shin Tokai University, School of Science, Professor, 理学部, 教授 (40191093)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | Broadband / Dielectric spectroscopy / Polymer / Molecular liquid / Alcohol / Solution / Glass transition / Relaxation |
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| Research Abstract |
In order to make clear the dynamics of polymer and molecular liquid in polymer solutions, broadband dielectric spectroscopy of the mixtures with polar polymer and solvent were measured in the frequency range of 30 GHz - 1μHz.
1. Dielectric relaxation of PVP-alcohol mixtures
BDS measurements were carried out for poly(vinyl pyrrolidone)(PVP)-alcohol mixtures with mono- and poly-hydroxyl alcohols at 25℃. The dielectric relaxation processes due to the molecular motions of alcohol and local chain motion PVP were observed in the frequency ranges of 2 GHz - 100 MHz and 10 MHz - 10 kHz, respectively. The relaxation times of mono-hydroxyl alcohols were determined by the density of hydrogen-bond, ρ_<HB>. On the other hand, the relaxation times of poly-hydroxyl alcohols were not determined by ρ_<HB>. These results imply that the mechanism which determines the relaxation time of mono-hydroxyl alcohols is different from that of the poly-hydroxyl alcohols. The relaxation time of PVP increases with the PVP concentration, since the increase of the interactions among the polymer chain makes the relaxation time larger. The relaxation time at the infinite dilution of PVP is proportional to the viscosity of poly-alcohol and proportional to 1.3 powers of that of mono-alcohols.
2. Dielectric relaxation of EGO-water mixtures on liquid to glass
BDS measurements of 65 wt% ethylene glycol oligomer (EGO)-water mixtures for various repeat units of EGO were carried out in the frequency range of 10 mHz - 10 GHz in the temperature range of 128 - 298K. According to these experimental results, the shape of dielectric loss peak observed in the liquid state is related to the cooperativity between water and EGO molecules and the separation scenario of the α- and β-processes in low temperature range close to the glass transition temperature.
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Report
(4 results)
Research Products
(40 results)
