| Project/Area Number |
22K14655
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 32020:Functional solid state chemistry-related
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| Research Institution | Hokkaido University |
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Principal Investigator |
Huang Rui-Kang 北海道大学, 電子科学研究所, 助教 (60901296)
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| Project Period (FY) |
2022-04-01 – 2024-03-31
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| Project Status |
Completed (Fiscal Year 2023)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2023: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2022: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
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| Keywords | Supramolecule / pyroelectricity / Structural flexibility / Thermal expansion / supramolecule / polarity / structural flexibility / Molecular pyroelectrics / Waste heat harvesting / Supramolecular crystals |
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| Outline of Research at the Start |
Waste heat recycling has been a huge challenge. One of the most promising solution is recycling them by pyroelectric materials that can generate current during temperature change. This research aims to demonstrate a novel strategy (polar axis deformation) for designing molecular pyroelectrics, and explore their applications for waste heat harvesting. In this research, the design-structure-pyroelectricity relationship will be discussed and prototype of energy harvesting will be made. Results may open up a new area of molecular pyroelectrics design and their application in energy problems.
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| Outline of Final Research Achievements |
Using 18-crown-6 (18C6) and 3-R-adamantane-1-aminium (HADA-R, R = H, F, Cl, Br, OH), a series of crystals were successfully synthesized. All of the (HADA-R)(18C6)ClO4 crystals contain similar 1D supramolecular columns structure. For R = H, both HADA-H and 18C6 are rotating above room temperature, while undergo rotational-freezing transitions around 253-333 K, resulting in the significant thermal expansions along polar axis as designed. For R = F, the HADA-F exhibit flipping motion in the 1D column with disordered NH3 and F at above 373 K, indicating the crystal may be ferroelectric at lower temperature. For R = Cl, the one-dimensional columns in the crystal were reverse-arranged so the polarity is canceled, and so does for R = Br. The R = Cl crystal showed negative-zero-positive thermal expansion associated with the rotation-swing-stationary transition of 18C6, whereas this transition was not observed in the R = Br crystal, which has a larger atomic radius.
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| Academic Significance and Societal Importance of the Research Achievements |
This research would a) enrich the design strategy of functional molecular materials, b) expand the area of high-performance pyroelectrics, and c) enlighten the application of molecular materials in energy problems.
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