| Project/Area Number |
09450282
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
化学工学一般
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| Research Institution | Tohoku University |
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Principal Investigator |
KONNO Mikio Tohoku University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (40125547)
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| Co-Investigator(Kenkyū-buntansha) |
佐藤 友章 東北大学, 大学院・工学研究科, 助手 (70261584)
顧 順超 東北大学, 大学院・工学研究科, 助手 (30292238)
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| Project Period (FY) |
1997 – 2000
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥16,000,000 (Direct Cost: ¥16,000,000)
Fiscal Year 2000: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥12,900,000 (Direct Cost: ¥12,900,000)
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| Keywords | electrorheology / particle / aggregate structure / dielectrics / dielectric permittivity / electroconductivity / suspension / 機能性材料 / エレクトロレオロジー効果 / 粒子分散系流体 / 誘電分極 / 電気伝導率 / 電気レオロジー流体 / 粒子鎖構造 / 伝導性電流 / 変位電流 / 電流特性 |
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| Research Abstract |
Materials of particles suspended in fluid are expected to change fluid properties and structures with an application of external electric and magnetic fields. Several properties of such fluid materials have been investigated experimentally and theoretically Electrorheological (ER) effects are typically observed in particle/insulating oil dispersions, whose shear stress can drastically increase with the external electric field applied. In the past, a number of mechanisms were proposed to explain such behavior. On the basis of the consideration of particle aggregation structures under the electric field, poor understanding of the mechanism makes it difficult to establish the grounding of material design of ER fluids. This project employed an ER fluid of silica particles or ferroelectric barium titanate particles suspended in electrically insulating silicone oil. In-situ measurements of dielectricity, electroconductivity and generated shear stress were performed under an application of alternative electric field. The generated shear stress was found to closely depend on the dielectric constant of the suspension. This finding has led to the derivation of a new correlation equation for the generated shear stress, the generated permittivity and the external electric field strength. It is verified that the equation can be applied for a wide variety of experimental conditions.
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