Microporous alumina substrate with porosity >70% by gelcasting

• Published in: Ceramics international Vol. 33; no. 4; pp. 515 - 520
• Main Authors: Prabhakaran, K., Priya, S., Gokhale, N.M., Sharma, S.C.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2007; Elsevier Science
• Subjects: Alumina; Applied sciences; B. Porosity; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Chemistry; Colloidal state and disperse state; Exact sciences and technology; Gelcasting; General and physical chemistry; Membrane substrate; Membranes; Miscellaneous; Technical ceramics; B. Porosity; Membrane substrate; Gelcasting; Alumina; Scanning electron microscopy; Tubular shape; Experimental study; Porous material; Oxide ceramics; Formaldehyde; Planar form; Colloidal gel; Casting; Urea; Gelling agent; Microporosity; Sintering; Technical ceramics; Manufacturing; Inorganic membrane
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2005.10.017

Microporous alumina membrane substrate in tubular and planar configurations have been prepared by gelcasting of alumina powder slurry using high amount of urea–formaldehyde as gelling agent followed by humidity controlled drying, binder removal and sintering of the gelled bodies. Porosity of the substrate samples sintered at 1350 °C was more than 70% as measured by mercury porosimeter. More than 51% porosity could be retained even after sintering of the samples at 1450 °C. Average pores size of the membrane substrate samples sintered at temperature in the range from 1250 to 1550 °C varied between 0.42 and 0.56 with a maximum at 1350 °C. More uniform pores were observed in sample sintered at 1450 °C. Urea-formaldehyde polymer present in the gelcast body acts as template for micropores.