Preparation and Properties of Porous α-Al2O3 Membrane Supports

✍ Scribed by Krenar Shqau; Matthew L. Mottern; Di Yu; Henk Verweij

• Book ID: 109259804
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 288 KB
• Volume: 89
• Category: Article
• ISSN: 0002-7820
• DOI: 10.1111/j.1551-2916.2006.01037.x

✦ Synopsis

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.