1996 Fiscal Year Final Research Report Summary
CARBON COATING OF METAL AND METAL OXIDE PARTICLES BY ARC DISCHARGE
| Project/Area Number |
07805090
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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 |
資源開発工学
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| Research Institution | AKITA UNIVERSITY (1996)
Tohoku University (1995) |
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Principal Investigator |
BALACHANDRAN Jeyadevan AKITA UNIVERSITY,MINING COLLEGE,MINING COLLEGE,DEPT.OF GEOSCIENCES,MINING ENG.& MATERIALS PROCESSING,LECTURER, 鉱山学部, 講師 (80261593)
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| Co-Investigator(Kenkyū-buntansha) |
TOHJI Kazuyuki TOHOKU UNIVERSITY,ENGINEERING FACULTY,DEPT.OF GEOSCIENCES AND TECHNOLOGY,ASSOCIA, 工学部, 助教授 (10175474)
FUJITA Toyohisa AKITA UNIVERSITY,MINING COLLEGE,MINING COLLEGE,DEPT.OF GEOSCIENCES,MINING ENG.&, 鉱山学部, 教授 (70124617)
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| Project Period (FY) |
1995 – 1996
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| Keywords | carbon coating / metal particle / magnetic particle / arc discharge / surfactant / sodium oleate |
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| Research Abstract |
The unstability of the metal particle surface in oxidizing atmosphere can be solved by coating the particle with carbon. In this project, we propose a novel method to produce the graphite like carbon layr on the surface of the particles. To obtain a graphite like layr of a few nanometer thick, first, the surfactant is adsorbed onto the particle and then reduced/decomposed by bombardment with ionized He atoms in the arc discharge chamber. In the initial stages of the project, instead of metal particles, magnetite particles (10nm) coated with oleate was treated in the arc chamber and the treated particles were characterized using TEM,FTIR,XRD and XPS.The results suggested that only the surface of the particle is influenced by the treatment and the surfactant is reduced to produce a graphite like layr around the particle and the dissolution of the coated particles in acid solution was lower compared to the non-treated particles. In the next stage, the experiments were performed on magneti
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te particle of micrometer size. The reason was to get closer to practical size used in magnetic recording etc., and make direct observation of the particle surface using SEM possible. The results were similar to the one we obtained with 10nm size magnetite. In the final stage, we studied the influence of different surfactants and protectiveness of the synthesized layr on iron particles. As for the surfactants, we used sodium oleate and Aerosol OT (Di-2-ethyl-hexyl Sodium Sulfosuccinate). Even in the case of metal particle, it was possible observe the carbon like later on the surface. Further, when the treated particles were exposed to oxidizing atmosphere (HCl vapor) and dissolution in diluted HCl, the decrease in saturation magnetization with time of exposure slowed down and the dissolution rate was also reduced compared to the non-treated particles. Sodium oleate was superior to Aerosol OT.The main problem of this method is that to improve the protectiveness, the treatment has to be repeated a number of times. We believe that this could be solved by selecting the surfactant that adsorbs strongly on metal and carbon surfaces and has large cross-sectional area and long chains. Less
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