2000 Fiscal Year Final Research Report Summary
Mechanism of Phase Separation of Polymar Blends Induced by a Gradient of Light Intersity
| Project/Area Number |
11650932
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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 |
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 |
SAKAI Wataru Kyoto Inst.Tech.Polymer Sci. & Engr. Research Associat, 繊維学部, 助手 (70263176)
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| Co-Investigator(Kenkyū-buntansha) |
MIYATA Taka-aki Kyoto Inst.Tech.Polymer Sci. & Engr. Associate Prof., 繊維学部, 助教授 (50188827)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Polymer Alloys / Phase Separation / Photoisomerization / Linearly polarized light / Symmetry-Breaking / Polystyrene / Poly (vinyl methyl ether) / ポリビニルメチルエーテル |
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| Research Abstract |
Phase separation of polymer mixtures has been extensively studied under conditions of translational and rotational invariance. As a consequence, phase separation proceeds homogeneously and isotropically with time and space. In this study, phase separation of a mixture composed of stilbene-labeled polystyrene (PSS) and poly (vinyl methyl ether)(PVME) was induced under symmetry-breaking conditions by using a distribution of light intensity. In the experiments where the translational invariance of concentration fluctuations was broken, uv light with a well-defined intensity gradient was used to induce the phase separation. Anisotropic morphology emerge with the preferred orientation almost perpendicular to the polarization direction (E). On the other hand, linearly polarized light was used to brake the rotational invariance of phase separation by taking advantages of the polarization-selective photoisomerization of stilbene.
In the first kind of experiments, the morphology induced by a gra
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dient of light intensity tends to develop exclusively along the direction perpendicular to the gradient. The phase separation in the upper stream of the intensity gradient proceeds with the kinetics almost similar to the case of using homogeneous intensity. On the ther hand, phase separation in the lower stream evolves much faster with irradiation time. The phase separation kinetics observed along the gradient is determined by the magnitude of the gradient and seems to be universal and independent from the light intensity.
In the second kind of experiments, linearly polarized light was used to produce an orientation distribution of the light intensity. The phase separation depends, now, on the relative orientation with respect to the direction E of the polarized light. It was found, in this particular case, that the phase separation proceeds fastest along the direction of E, whereas it becomes very slow along the perpendicular direction.
Combined with the data obtained previously with experiments using a temperature gradient (Physica D 84, 23, 1995), the results obtained in this study suggest a new and efficient way to design polymers with controllable graded structures. Less
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Research Products
(14 results)
