| Project/Area Number |
60550554
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機工業化学
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| Research Institution | Okayama University |
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Principal Investigator |
MIURA Yoshinari Professor, School of Engineering, Okayama University, 工学部, 助教授 (80032952)
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| Co-Investigator(Kenkyū-buntansha) |
OSAKA Akiyoshi Associate Professor, School of Engineerng, Okayama University, 工学部, 助教授 (20033409)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1986: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1985: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Molten glass / Electrochemistry / Acid-base / Electrode potential / Oxygen ion concentration cell / 溶媒和エネルギー |
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| Research Abstract |
There have been many attempts to determine the oxygen ion activity of oxide glass, such as measurement of gaseous solubility, optical absorption of transition metal ions, determination of oxidation-reduction equilibrium, measurement of nephelauxetic effect and emf measurement of concentration cell. The last one is the most useful method for the molten state. The emf of a concentration cell, for example, Pt: <O_2> | <Na_2> 0.2 <B_2> <O_3> (reference)|| <Na_2> O- <B_2> <O_3> | <O_2> :Pt is given by the Nernst type equation. The oxygen ion activity of the test melt can be calculated from the equation, [ <O^(2-)> ]=exp(-2FE/RT). The emfs of Pt: <O_2> | <Na_2> 0.2 <B_2> <O_3> ||x <R_2> O-(1-x) <B_2> <O_3> | <O_2> :Pt and Pt: <O_2> | <Na_2> 0.2Si <O_2> ||x <R_2> O-(1-x)Si <O_2> | <O_2> :Pt (where R=Li,Na,K and Cs) were measured by using the electrolytic bridge made of double platinum crucibles in which the smaller one has a pinhole. The oxygen ion activity increases with increasing alkali oxide content as well as with the order of <Li^+> < <Na^+> < <K^+> < <Cs^+> . However, for Li- and Na- borate systems there is the respective clear-cut minimum around x=0.2, which suggests the existence of the boron anomaly even in the melt. The standard reduction potentials of <Ni^(2+)> / <Ni^0> and <Sb^(5+)> / <Sb^(3+)> in x <Na_2> O.(1-x) <B_2> <O_3> melt (x=0.1-0.4) referred to the platinum oxygen electrode in <Na_2> 0.2 <B_2> <O_3> increased negatively with increasing sodium oxide content. The solvation energy calculation showed that the reactivity between these ions and oxygen ions became larger with increasing basicity of the melt.
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