Structural relaxation in amorphous molecular systems' Studies with conformation
| Project/Area Number |
17550018
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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 |
Physical chemistry
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| Research Institution | Gakushuin University |
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Principal Investigator |
ISHII K. Gakushuin University, Faculty of Science, Professor, 理学部, 教授 (30013543)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAYAMA H. Gakushuin University, Faculty of Science, Research Associate, 理学部, 助手 (00155889)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2006: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2005: ¥3,400,000 (Direct Cost: ¥3,400,000)
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| Keywords | amorphous / structural relaxation / Raman spectra / conformation isomer / crystallization / glass transition / 1,2-dichloroethane / butyronitrile |
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| Research Abstract |
We have been studying structure and structural relaxation in amorphous molecular systems prepared by vapor deposition onto cold substrates. In this two-years project, we have studied the relaxation of samples made of compounds that have conformation isomers to elucidate the interrelation between the molecular structural change and the change in intermolecular configuration.
In the first year, we improved the vacuum system to carry out the. Raman measurements on the amorphous samples under the condition with less amount of the contamination. Along with this work, we tried the measurements on 1,2-dichloroethan (DCE), and found interesting phenomena that the gauche molecules of DCE increased with the temperature elevation even in the solid amorphous states.
In the second year, we continued the study on DCE in detail. From the quantitative estimation of the gauche mole fraction, we found that the temperature at the sample surface on deposition of room-temperature vapor was as small as few Kelvin. The rate of the increase of gauche was small in the initial period of temperature elevation, but it was accelerated above a certain region of temperature depending on the deposition temperature. Taking all such experimental results into consideration, we made a detail discussion on the relaxation process of amorphous DCE, and reported it in J.Phys.Chem.B. We also studied the relaxation of amorphous butyronitrile that has conformation isomers similar to those of DCE. In this study, we found that the temperature change of the wavenumber of a Raman-band turned to the opposite direction at the glass-transition temperature T_g. This was the first observation by which a glass transition was confirmed by spectroscopic measurements. We reported these results in J.Non-Cryst.Solid. For the moment, we are further studying a new phenomena that the relaxation behavior is different from ordinary ones when we prepare the samples at temperatures close to T_g.
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Report
(3 results)
Research Products
(9 results)
