| Project/Area Number |
63440013
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
林産学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
OKANO Takeshi The Univ. of Tokyo, Fac. of Agric., 農学部, 教授 (30011927)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIWARA Hiroshi The same as above, Research Assoc., 農学部, 助手 (30210751)
MISHIRO Akiyoshi The same as above, Research Assoc., 農学部, 助手 (90012004)
OHTA Masamitsu The same as above, Assoc. Prof., 農学部, 助教授 (20126006)
ISOGAI Akira The same as above, Research Assoc., 農学部, 助手 (40191879)
KUGA Shigenori The same as above, Research Assoc., 農学部, 助手 (60012051)
SUGIYAMA Junji The same as above, Research Assoc., 農学部, 助手 (40183842)
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| Project Period (FY) |
1988 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥29,700,000 (Direct Cost: ¥29,700,000)
Fiscal Year 1991: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1990: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1989: ¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1988: ¥20,600,000 (Direct Cost: ¥20,600,000)
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| Keywords | cellulose crystal / electron diffraction / X-ray diffraction / Valonia / ramie / mercerization / magnetic field / polymorphism / セルロ-ス / 結晶構造 / 木材セルロ-ス / バクテリアセルロ-ス / バロニアセルロ-ス / 磁場 / ホヤ / 電子顕微鏡 / 単結晶 / セルロースII / セルロース誘導体 |
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| Research Abstract |
Following results were generated during 4 years of intensive research.
1) 2 types of native celluloses categorized by ^<13>C-NMR, namely the Bacterial-Valonia type and the Cotton-Ramie type, were investigated by electron diffraction. They were assigned to the mixtwe of triclinic and monoclinc phases and the single phase of monoclinic, respectively. 2) The triclinic unit contained only one chain in it. Accordingly all the chains in one microfibril had the same polifity. The entirely new model were thereby proposed, which was a good alternative of 8-chain unit cell by Honjo-Watanbe. 3) Among woody celluloses such as those from softwoods, hardwoods, and bamboos, we have pointed out the difference in their diffraction intensities and dspacing data. The discriminant analyses based on those data showed that the holocelluloses of woody samples (17 softwoods and 61 hardwoods) were all categafift to the Cotton-Ramie type, although some of them (15 softwoods and 7 hardwoods) were once classified to the Bacterial-Valowa type before purification. There still remains, however, certain differences between softwoods and hardwoods. 4) Mercerization of cellulose, the transformation of cellulose I into II, is known to be an irreversible process. Having investigated intermediate crystalline alkaline celluloses in the early stage of swelling, we concluded that the fully swollen cellulose cannot go back to cellulose I. 5) Mercerization of dispersed microcrystalline cellulose was investigated by electron microscopy and x-ray diffraction. The change of crystalline state accompanied remarkable morphological changes such as the formation of cracks along microfibrils and the formation of bead-like particles. 6) The diamagnetic orientation behavior of the aqueous suspension of cellulose microcrystals was investigated When the strong magnetic field was applied, the crystals oriented perfectly, being their fiber axes perpendicular to the magnetic field.
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