2004 Fiscal Year Final Research Report Summary
Development of preparation of core-shell particles and their ordering
| Project/Area Number |
15560594
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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 | Tohoku University |
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Principal Investigator |
KOBAYASHI Yoshio Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (40250849)
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| Project Period (FY) |
2003 – 2004
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| Keywords | silica / particle / encapsulation / polystyrene / dip-coating / Mie theory / ordering |
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| Research Abstract |
For preventing aggregation and damage of particles, silica-coating has been proposed. Ag nanoparticles with a size of 10 nm, Au nanoparticles with a size of 15 nm and Co nanoprticles with a size of 20 nm were successfully coated with silica with a modified Stober method. Silica shell thickness was varied with varying concentration conditions. Photo-properties for the silica-coated Ag and Au nanoparticles could be explained with a Mie theory. The silica-coated Co nanoparticles showed magnetic properties different from bulk materials. The proposed method could be also extended to silica -coating AgI nanopartides and fluorescent microspheres.
Mono-layering of sub-micron-sized polystyrene and silica spheres on glass substrates by a dip-coating technique has been demonstrated. For the mono-layering the spheres in a hexagonal close-packed structure on the substrates, it was necessary to reduce ionic strength of dispersion of the colloidal suspension. Multi-layering of the spheres was achieved by repeating the dip-coating process. For the case of large spheres layered on small ones, the large spheres were mono-layered on the mono-layer of the small spheres just as spheres were mono-layered on a flat surface. For the case of small spheres layered on large ones, the small spheres were located in void along periphery of the large spheres.
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Research Products
(11 results)
