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Coagulation of Concentrated Suspensions of Ultrafine Alumina Powders by pH Shift
Author(s) -
Pénard AnneLaure,
Rossignol Fabrice,
Pagnoux Cécile,
Chartier Thierry,
Cueille Christophe,
Murphy Matthew E.
Publication year - 2006
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.1551-2916.2006.00940.x
Subject(s) - coagulation , dispersant , acetic acid , acetic anhydride , chemical engineering , ethylene glycol , kinetics , viscosity , chemistry , materials science , nuclear chemistry , catalysis , organic chemistry , dispersion (optics) , composite material , psychology , physics , quantum mechanics , psychiatry , optics , engineering
Highly concentrated suspensions of ultrafine alumina powders are prepared using 2‐phosphonobutane‐1,2,4‐tricarboxylic acid as dispersant. The coagulation of these suspensions is carried out at around 278 K by adding a blend of acetic anhydride plus ethylene glycol. Coagulation takes place through a pH shift because of a time‐delayed hydration of the acetic anhydride. The coagulation kinetics are studied by viscosity measurements with respect to the temperature and composition of the coagulant blend. Finally, the method is used to produce complex 3D parts of large dimensions for bio‐applications by direct coagulation casting and the fired bodies are characterized.