2002 Fiscal Year Final Research Report Summary
Preparation of novel ultrafine particles having solar energy conversion and storage ability and their application for composites
| Project/Area Number |
13650745
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Composite materials/Physical properties
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| Research Institution | NIIGATA UNIVERSITY |
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Principal Investigator |
TSUBOKAWA Norio NIIGATA UNIVERSITY Faculty of Engineering, Professor, 工学部, 教授 (20018675)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Ultrafine silica / Carbon black / Hyperbranched poly(amidoamine) / Surface grafting / Hyperbranched polyester / Composites / Norbornadiene / Solar energy conversion and storage |
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| Research Abstract |
The grafting of hyperbranched poly(amidoamine) (PAMAM) from the silica and carbon black surface was achieved by repeating two steps in solvent-free dry-system: (1) Michael addition of methylacrylate to amino groups on the surface and (2) amidation of terminal groups with ethylenediamine. Hyperbranched polyester was also grafted onto silica and carbon black surface by self condensation of bis(2-hydroxymethyl)propionic acid using p-toluenesulfonic acid as catalyst in the presence of silica having amino groups.
The immobilization of norbornadiene (NBD) moieties onto silica and carbon black surface by the direct condensation of the surface terminal amino groups of hyperbranched PAMAM-grafted silica with 3-phenyl-2, 5-norbornadiene-2-carboxylic acid (NBD-COOH) was examined. It was found that the immobilization of NBD moieties onto silica and carbon black successfully proceeded in the presence of N, N'-dicyclohexylcarbodiimide (DCC) as a condensing agent. The immobilized NBD moieties onto the silica increased with increasing amount of amino groups of hyperbranched PAMAM-grafted silica, but the percentage of amino groups used for the immobilization of NBD moieties was decreased.
The immobilization of NBD moieties onto silica and carbon black surface was achieved by the direct condensation of the surface terminal hydroxyl groups of hyperbranched polyester-grafted silica and carbon black with NBD-COOH in the presence of DCC.
The immobilized NBD moieties on silica and carbon black were readily isomerized to quadricyclane (QD) by photo-irradiation in n-hexane. Stored thermal energy by QD-immobilized silica and carbon black was released as thermal energy by heating. The stored thermal energy of QD-immobilized silica increased with progress of the photo-irradiation time and became constant, about 30 J/g-silica, after 2 h.
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