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Ceramic Capillary Suspensions: Novel Processing Route for Macroporous Ceramic Materials
Author(s) -
Dittmann Jens,
Koos Erin,
Willenbacher Norbert
Publication year - 2013
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/jace.12126
Subject(s) - capillary action , ceramic , suspension (topology) , materials science , porosity , porous medium , composite material , particle size , yield (engineering) , phase (matter) , particle (ecology) , chemical engineering , chemistry , oceanography , mathematics , homotopy , pure mathematics , engineering , geology , organic chemistry
We introduce a novel method to produce macroporous ceramics by capillary suspensions. Adding a small amount (~1 vol%) of an immiscible secondary phase to a low concentration (~20 vol%) suspension can increase the yield stress by several orders of magnitude. This drastic change in flow behavior is induced by the creation of a sample‐spanning particle network in the suspension controlled by capillary forces. This strong network may persist even if the primary bulk phase is removed. Accordingly, capillary suspensions can be used as a precursor for manufacturing porous materials. Here, we focus on the specific features of this universal, low‐cost processing route for porous ceramics. An Al 2 O 3 model system is used to demonstrate how to adjust porosity and pore size. With this system, we were able to achieve open porosities higher than 60% with an average pore size below 10 μm.