2000 Fiscal Year Final Research Report Summary
Studies on Volume Phase Transition and Transition Dynamics of Polymer Gels
| Project/Area Number |
10305069
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| Research Category |
Grant-in-Aid for Scientific Research (A).
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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 UNIVERSITY |
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Principal Investigator |
MASUDA Toshiro Kyoto Univ., Dept.of Mat.chem., Prof., 工学研究科, 教授 (10026007)
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| Co-Investigator(Kenkyū-buntansha) |
ARAKI Osamu Kyoto Univ., Dept.of Mat.Chem., Instr., 工学研究科, 助手 (50303863)
TAKIGAWA Toshikazu Kyoto Univ., Dept.of Mat.Chem., Ass Prof., 工学研究科, 助教授 (50201603)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Diffusion constant / Second-order transition / First-order transition / Phase diagram / Heat of transition / DSC / Poly (N-isopropylacrylamide) |
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| Research Abstract |
Swelling and deswelling kinetics of poly (N-isopropylacrylamide)(PNIPA) gels was investigated by using a temperature jump method. In the course of swelling of the gels showing the continuous transition, the diffusion constant decreases with approaching the transition temperature. This behavior was observed for the gels showing continuous and discontinuous volume change. The diffusion constant obtained in the course of deswelling agreed well with that obtained for swelling if the gels lay in the swollen phase. However, the diffusion constant depended strongly on the volume strain when the gels were in the collapsed phase. The effects of the application of load on the transition behavior of PNIPA gels were also investigated. The plots of transition temperature against load were found to correspond to the phase boundary between the swollen and collapsed phases of the gels. Namely, the dependence curve corresponded to the phase diagram if the analogy to the van der Waals fluids was employed. The analogy leaded successfully to the estimation of the transition enthalpy by using the Clapeyron equation.
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