2002 Fiscal Year Final Research Report Summary
Chirality selection and branching mechanism in the pattern formation of polymer crystals
| Project/Area Number |
13640386
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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 |
物性一般(含基礎論)
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
TODA Akihiko Hiroshima University, Faculty of Integrated Arts and Sciences, Associate Professor, 総合科学部, 助教授 (70201655)
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| Co-Investigator(Kenkyū-buntansha) |
HIKOSAKA Masamichi Hiroshima University, Faculty of Integrated Arts and Sciences, Professor, 総合科学部, 教授 (60087103)
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| Project Period (FY) |
2001 – 2002
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| Keywords | polymer / banded spherulites / chair-type single crystal / atomic force microscopy / PVDF / polyethylene |
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| Research Abstract |
We have examined the chirality selection and branching mechanism in the pattern formation of higher order structure of polymer crystals. We focused on the structure of banded spherulites, in which a concentric ring pattern is spontaneously generated. We examined the structure in polyethylene and PVDF, which do not have chirality in the molecular chain, by optical and atomic force microscopies.
1. We have examined the free surface of a banded spherulite of poly (vinylidene fluoride) (PVDF) by an atomic force microscopy. The directions of the slope of multilayer terraces of lamella crystals are kept in each half of a banded spherulite, and this evidence confirms the macroscopic selection of one of the handedness in the formation of spiral terraces in each growth direction of a banded spherulite of PVDF.
2. The three-dimensional morphology of polyethylene single crystals grown from dilute solution has been examined by atomic force microscopy. The observation of single crystals on dried PVA clarifies the morphology of chair type crystal as well as well-known hollow pyramidal type. It has been confirmed that the screw dislocations in the chair type follow a selection rule of the handedness in a manner to relieve the distortion in the chair type.
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