| Project/Area Number |
18K19125
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 36:Inorganic materials chemistry, energy-related chemistry, and related fields
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
NAKAJIMA Akira 東京工業大学, 物質理工学院, 教授 (00302795)
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| Co-Investigator(Kenkyū-buntansha) |
酒井 宗寿 茨城大学, 研究・産学官連携機構, 准教授 (00392928)
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| Project Period (FY) |
2018-06-29 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2020: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2019: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | ライデンフロスト / 磁性流体 / ラチェット / 核沸騰 / 重力 / 酸化亜鉛 / ナノロッド / 撥水 / 発電 / エネルギー |
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| Outline of Final Research Achievements |
Zinc oxide nanorods (ZnO-NR) were prepared onto Si wafer by hydrothermal process.The Leidenfrost point against water droplet for ZnO-NR exhibited a trend to decrease with increasing contact angle, however it depended on solid-liquid contact area ratio. The self-propulsion of water droplets on a Zn plate with a ratchet structure was nucleate boiling (160-200oC) and gravity (200oC<) . Both the temperature for self-propulsion and the velocity of the self-propelled droplets were decreased by ZnO-NR modification of the Zn plate surface with a ratchet structure. The dominant driving force of the droplet motion on the sample surface was inferred as gravity. The sample modified with ZnO-NR onto every other ratchet attained self-propulsion with low temperatures and high moving velocity simultaneously, suggesting the importance of the roughness arrangement for the ratchet structure. Electromotive force was obtained by using a magnetic fluid and Leidenfrost ring.
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| Academic Significance and Societal Importance of the Research Achievements |
現状での廃熱利用は既存技術で利用しやすい400oC以上の高温廃熱が中心であり、300oC以下の低温廃熱は、十分に利用されているとは言えない。この温度域の熱エネルギーは技術的に回収が行いにくく、その有効利用のための技術開発が求められている。本研究では、この温度領域で発現する「ライデンフロスト現象：液体が沸点よりも高温度の固体表面に接触した際に、液体が揮発することで蒸気膜が形成され浮遊する現象。その結果、液体の急激な蒸発が抑制される効果」に着目し、この現象を効果的に固体材料表面上に発現させ、液滴の回転運動を誘起することで、従来困難であった100～300oCの廃熱の回収を可能にする。
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