| Project/Area Number |
11650710
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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 |
Composite materials/Physical properties
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| Research Institution | Nihon-University |
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Principal Investigator |
YANO Shoichiro Nihon-University, Collage of Science & Technology, Professor, 理工学部, 教授 (50297777)
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| Co-Investigator(Kenkyū-buntansha) |
KURITA Kimio Nihon-University, Collage of Science & Technology, Professor, 理工学部, 教授 (50059648)
SAWAGUCHI Takashi Nihon-University, Collage of Science & Technology, Associate Professor, 理工学部, 助教授 (20102551)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Bacterial cellulose / Ornanic-inorganic hybrid / Sol-gel process / Silica / Biomimetic / Dynamic viscoelaticity / Tensile properties / Water sorption / ゾルーゲル法 / シリカゲル / 圧縮クリープ / 圧縮応力緩和 / ハイドロゲル |
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| Research Abstract |
The BC gel/SiO_2 hybrid was prepared by mixing BC gel with aqueous solution of silanol from tetraethoxysilene (TEOS). BC was cultured by using Acetobacter xylinum at 30℃ for 25 days. Evaluation of the BC gel was carried out by compression creep and stress relaxtion measurements. Change in the creep deformation with time was approximated by three elements model consisting of a spring and a Voigt model in series. Change in the strain γ(t) with time can be calculated by γ(t)=γ_1+γ_2 [1-exp(-t/λ)], where γ_1 is instantaneous strain at t=0, γ_2 is equilibrium strain at t=∞, and λ is the retardation time. This hybrid was hard, and deformation became small with short λ value, if compared with BC gel. Compression stress relaxation of cellulose hydro-gel was also measured in water. Stress σ(t) decreased with time, and approximated by σ(t)=Σ^^<3-4>__<i=1>σ_iexp(-t/τ_i). Where τi is relaxation time and calculated by use of procedure X proposed by Tobolsky, Relaxation times decreased with SiO_2 content in the hybrids. This tendency is the same as creep results. BC/Si0_2 hybrid films were obtained by hot-pressed at 120℃. The tensile strength of the BC hybrid film was increased from 123 MPa to 160 MPa at 10 % and 178 MPa at 20 % TEOS.The modulus of the hybrid was also improved to 40 GPa at 20 % TEOS from 20 GPa.
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