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Effect of Core Materials on the Formation of Hollow Alumina Microspheres by Mechanofusion Process
Author(s) -
Kato Takayuki,
Ushijima Hitoshi,
Katsumata Makoto,
Hyodo Takeo,
Shimizu Yasuhiro,
Egashira Makoto
Publication year - 2004
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2004.00060.x
Subject(s) - materials science , polymer , microsphere , core (optical fiber) , sintering , composite material , mass fraction , particle (ecology) , thermal decomposition , methyl methacrylate , chemical engineering , particle size , shell (structure) , particle size distribution , copolymer , chemistry , organic chemistry , oceanography , engineering , geology
Core/shell structures have been prepared via a mechanofusion system by employing several kinds of spherical polymers as a core material and Al 2 O 3 powder or a mixture of Al 2 O 3 and SiO 2 powders as a shell material. The effect of the kind of core polymers on the quality of the resulting hollow alumina microspheres has been discussed on the basis of the thermal decomposition behavior of spherical polymers used as a core material. A large fraction of hollow alumina microspheres reflecting the shape and the particle size distribution of the core polymer could be fabricated after sintering at 1600°3C for 3 h, when highly cross‐linked poly(methyl methacrylate) (PMMA) microspheres with a gel fraction of 99.03% were used as a core polymer, and abrupt firing at temperatures higher than 500°3C was adopted to remove the PMMA microspheres. The addition of 5 mass% SiO 2 to the Al 2 O 3 shell layer was found to be useful for maintaining the spherical shell structure during the firing process and for fabricating a large fraction of hollow alumina microspheres after the sintering.