| Project/Area Number |
17K06210
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | Chuo University |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 過冷度 / 氷の付着量 / 非イオン性界面活性剤 / イオン性界面活性剤 / 界面制御 / pH / 印加電圧 / 等電点 / せん断応力 / アニオン系界面活性剤 / 表面エネルギー / 過冷却 / 界面活性剤 / 固液相変化 / 熱工学 |
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| Outline of Final Research Achievements |
When two kinds of water mixtures with different nonionic surfactants were mixed, influence of molecular size of each surfactant on average supercooling degree of the mixed mixture was larger than that of the mixing method.
When an anionic surfactant mixture froze on a copper, the shearing stress defined as (ice adhesion force /ice adhesion area) increased with increase in a plus applied voltage. Further, even if no applied voltage (0V), the shearing stress became plus value by difference between the pH values of the mixture and the isoelectric point of the copper. When a minus voltage was applied, the shearing stresses measured were always lower than that of ice made from pure water regardless of applied voltage and they were constant. And surfactant molecules were charged by variation of pH values of the mixture so that its critical micelle concentration and average supercooling degree varied. So, the anionic surfactant was effective to suppress supercooling dissolution.
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| Academic Significance and Societal Importance of the Research Achievements |
氷の大きな冷熱を利用した冷蔵・冷却は有効であり，水産物，農産物や食品の冷蔵輸送，バイオ，薬品，化学製品等の製造過程での冷却や臓器冷却などその適応範囲は極めて広い．そのため，氷の効率的生成が重要となるが，その効率的生成の最大の阻害因子である過冷却と冷却面への氷の付着に対するより高度な制御技術の確立が重要となる．
そこで，界面活性剤やイオン性界面活性剤の分子の寸法効果や印加電圧とその極性を変えることで，界面活性剤分子の界面吸着特性を能動的に制御により,過冷度と付着力制御が可能なことを明らかにした．その結果より，過冷度と付着力をより効果的に制御することを工学的に広く実現する技術の確立が実現できた．
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