| Project/Area Number |
06640757
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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 |
機能・物性・材料
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| Research Institution | Meisei University |
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Principal Investigator |
HIDAKA Hisao Meisei Univ., Fac.Sci.& Eng.Professor, 理工学部, 教授 (70062312)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Photodegradation / Photooxidation / Titanium dioxide / Semiconductor / Polymer / Amino acid / DNA / RNA |
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| Research Abstract |
The research is composed of two sections ; (1) Photooxidation of solid polymers (polyvinylchloride PVC) and water-soluble polymers (PEG and PVA) (2) Photooxidation of biopolymers such as DNA,RNA,bases and polyamino acids.
(1) The photocatalyzed oxidative decompositions of solid particles of PVC and a PVC film have been examined in suspensions of titania or zinc oxide illuminated by UV light and/or by solar exposure. Dechlorination and evolution of carbon dioxide were monitored, the latter occurring by the intermediacy of acetic and formic acids. The photodegradation of polymer specimens was enhanced in TiO_2-water media by such added oxidants as hydrogen peroxide and potassium persulfate. Photocorrosion of these particulates was also examined by scanning electron microscopy. Water-soluble polymers of PEG and PVA were also photodegraded to CH_3COOH,HCOOH and CO_2 gas via hydroxyl and/or aldehydes.
(2) The sensitized photochemistry of DNA and RNA has been examined under UV-A and UV-B radiation in the presence of a physical sunscreen agent, TiO_2 anatase/rutile particles, to assess the possible damage that such an agent might cause on contact with such substrates. These two nucleotides are partially decomposed to carbon dioxide and the nitrogen are converted to ammonia and nitrate ions. The physical and chemical damage done to DNA was confirmed by TEM and SEM,and gel permeation chromatography. In addition, the fate of nitrogen in various amino acids was also examined as a fundamental research. The nitrogen in the amino acids are photoconverted predominantly into NH_4^+ and to a lesser extent into NO_3^- ions.
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