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Preparation and Properties of Porous α‐Al 2 O 3 Membrane Supports
Author(s) -
Shqau Krenar,
Mottern Matthew L.,
Yu Di,
Verweij Henk
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.1551-2916.2006.01037.x
Subject(s) - porosity , materials science , particle size , slurry , filtration (mathematics) , colloid , permeability (electromagnetism) , adsorption , particle size distribution , permeation , sintering , chemical engineering , membrane , shrinkage , colloidal silica , mineralogy , chemistry , composite material , organic chemistry , biochemistry , statistics , mathematics , engineering , coating
Strong and permeable macro‐porous α‐Al 2 O 3 membrane supports are made by colloidal filtration of 20 vol% dispersions of α‐Al 2 O 3 with an average particle size of 600 nm. Intact compacts with very good surface quality were obtained at an optimum pH of 9.5 and dosage of 0.2 wt% ammonium aurintricarboxylate (Aluminon), based on dry alumina. The colloidal stability of the aluminon‐stabilized slurries is confirmed by ξ potential measurements. Slight sintering of dense‐packed α‐Al 2 O 3 compacts was found to result in >67% packing density and a bimodal pore‐size distribution as derived from shrinkage behavior and gas adsorption studies. Non‐stationary single gas permeation measurements showed improved gas permeability, compared with α‐Al 2 O 3 compacts prepared using powder with a smaller particle size (300 nm). The strength of the disk‐shaped alumina compacts within the porosity range of 30%–20% increased from 100 to 300 MPa with a standard deviation of 20 and 50 MPa, respectively.