2023 Fiscal Year Final Research Report
Study on rheology of liquids with multiscale structures by means of high-frequency shear impedance spectroscopy
| Project/Area Number |
19K03768
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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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| Review Section |
Basic Section 13040:Biophysics, chemical physics and soft matter physics-related
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
松岡 辰郎 名古屋大学, 工学研究科, 准教授 (60252269)
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| Project Period (FY) |
2019-04-01 – 2024-03-31
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| Keywords | 粘弾性 / マルチスケール / 構造緩和 / 横波超音波 / 高粘性液体 / レオロジー |
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| Outline of Final Research Achievements |
An experimental method was developed to measure the frequency-dependent complex shear viscosity in the frequency range from 65 MHz to 3 GHz using an electrodeless quartz transducer. Calibrating the effects of dielectric responses of sample liquids by means of equivalent circuit method, we could obtain the shear relaxation spectrum consistent with those determined by conventional QCM-D method between 5 - 205 MHz. The novel method was then applied to various viscous liquids including room-temperature ionic liquids, water-in-salt electrolyte, polymer solution and nanofluids. Comparing the obtained shear relaxation spectra with the frequency-dependent volume viscosity determined by ultrasonic spectroscopy and the structural relaxation measured by quasi-elastic neutron scattering spectroscopy, we analyzed the origin of the shear viscosity of these liquids and the spatial dimension of the microscopic structure that determines the shear viscosity.
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| Free Research Field |
化学物理
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| Academic Significance and Societal Importance of the Research Achievements |
本研究で開発した手法により、5 MHz - 3 GHzという高周波領域、ほぼ3桁にわたる広帯域の粘弾性緩和測定が可能となり、粘度数十mPa sの液体のレオロジーを解析することが出来るようになった。レオロジー測定は粘性の微視的機構の解明に有力な実験手法であり、本研究成果は液体の粘性に対する新たな実験的研究手法を与えるものとなる。対象となる液体はイオン液体や濃厚電解液、コロイド溶液や高分子溶液など幅広く、これらの液体を工業的に用いる上で粘性が重要な物性となる場面も多いため、粘度を制御する材料設計の基礎となる情報を与える研究としての社会的意義も有する。
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