1999 Fiscal Year Final Research Report Summary
Studies on Reaction Kinetics and Structure of Polymer Gels by Photon Correlation Spectroscopy
| Project/Area Number |
09450362
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
SHIBAYAMA Mitsuhiro Faculty of Textile Science, Kyoto Institute of Technology, Professor, 繊維学部, 教授 (00175390)
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| Project Period (FY) |
1997 – 1999
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| Keywords | polymer gels / inhomogeneities / Static inhomogeneities / nonergodicity / dynamic light scattering / small-angle neutron scattering / photon correlation spectroscopy / time-resolved dynamic light scattering |
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| Research Abstract |
Frozen (static) inhomogeneities as well as thermal (dynamic) concentration fluctuations are present in gels. We proposed a relevant method to characterize and decompose the two contributions, i.e., the frozen inhomogeneities and thermal fluctuations. This method consists of dynamic light scattering measurements at hundreds of sample positions. This is called the ensemble-average dynamic light scattering (EADLS). Another highlight of this work is the four methods of determining a gelation threshold. During a chemical reaction undergoing cross-linking, four characteristic features appear at the gelation threshold; (i) an abrupt increase in the scattered intensity, (ii) a power-law behavior in the time-intensity correlation function (ICF), (iii) a characteristic broadening of the decay time distribution function, and (iv) a deviation of the initial amplitude of ICF from unity. The validity of these methods was examined for organic chemical gels, inorganic silica gels, and thermoreversible physical gels. I believe that these works promise a rich field in soft matter physics, as the science of connectivity-correlated polymeric materials.
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