2004 Fiscal Year Final Research Report Summary
Preparation and Structural Analysis of Nanocomposites of Bacterial Cellulose and Native Inorganic Material
| Project/Area Number |
15510101
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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 |
Nanomaterials/Nanobioscience
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| Research Institution | Kyoto University |
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Principal Investigator |
HIRAI Asako Kyoto University, Institute for Chemical Research, Assistant Professor, 化学研究所, 助手 (20156623)
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| Co-Investigator(Kenkyū-buntansha) |
HORII Fumitaka Kyoto University, Institute for Chemical Research, Professor, 化学研究所, 教授 (70124758)
TSUJI Masaki Kyoto University, Institute for Chemical Research, Associate Professor, 化学研究所, 助教授 (60172003)
DONKAI Nobuo Niigata Women's College, Department of Human Life and Environmental Science, Professor, 生活科学科, 教授 (90237181)
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| Project Period (FY) |
2003 – 2004
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| Keywords | cellulose / imogolite / nanocomposite / lipuid crystal / TEM / SEM / Polarizing Optical Microscopy / X-ray Diffraction Analysis |
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| Research Abstract |
To fabricate an environmentally friendly and new material, nanocomposites composed of cellulose microfibrils and imogolite nanotubes were prepared, and their structure and properties were investigated. First, tunicate cellulose was used as a cellulose sample. Tunicate cellulose microfibrils prepared by sulfuric acid treatment were rodlike in appearance, 1.9 μm long and 25 nm wide on the average. Raw materials of imogolite gel films were collected from a pumice bed at Murasakino, Kitakami-shi, Iwate-ken. Purified imogolite nanotubes with an outer diameter of 2.5 nm were estimated at 0.18 μm long on the average. Liquid crystal structures of the mixtures of tunicate cellulose microfibrils/imogolite nanotubes with different weight ratios in the aqueous solution of acetic acid (pH=3) were studied by polarizing optical microscopy and SEM. The texture of liquid crystal of imogolite showed a chiral nematic fingerprint pattern, while that of cellulose microfibrils gave cross-hatch pattern. All the textures of liquid crystals of the mixtures with different weight ratios were different from either texture of a single component of imogolite or cellulose microfibrils. The structure of nanocomposite films prepared from respective liquid crystalline phases of the mixtures was investigated by X-ray diffraction analysis and FT-JR. The storage modulus, E', at room temperature was 9.6,11,13,15 GPa for cellulose, 5/5,4/6, and 3/7 nanocomposites films, respectively. The values of E' were insensitive to the temperature above 25℃ for the 5/5 nanocomposite and cellulose films. The 5/5 nanocomposite film was broken at 290℃, while the cellulose film was broken at 250℃. The thermal properties were improved by adding imogolite. On the basis of the results of tunicate/imogolite nanocomposites, a study of bacterial cellulose/imogolite nanocomposites is in progress.
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