Abstract
Well-defined macroporous ceramics consisting of SiO2, TiO2 and ZrO2
have been fabricated via a template-assisted colloidal processing
technique. Close-packed polymer spheres were first prepared as a
template using centrifugation or gravitational sedimentation, followed
by infiltration with alkoxide precursors. The centrifugation should
be preferred because it is a less time-consuming process and the
materials are better ordered. The removal of the template beads was
achieved by calcination of the organic-inorganic hybrids at appropriate
temperatures, yielding well-ordered macroporous ceramics. The arrangement
of the porous structures could be changing the preparation of the
packed polymer templates. Some novel arrangements of macropores were
obtained in these macroporous ceramics: a simple square-packed arrangement
for SiO2, the coexistence of hexagonal close-packed and simple close-packed
arrangements for TiO2, and face-centered cubic packed arrangement
for ZrO2. The resulting highly structured ceramics could have applications
in areas ranging from quantum electronics to photocatalysis and battery
materials. (c) 2005 Elsevier Ltd. All rights reserved.
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