Fabrication and microstructure of Al2O3-TiO2 composite membranes with ultrafine pores

• Published in: Ceramics international Vol. 24; no. 1; pp. 25 - 30
• Main Authors: BAE, D.-S, CHEONG, D.-S, HAN, K.-S, CHOI, S.-H
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Science 1998
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Membranes; Scanning electron microscopy; Aluminium Oxides; Transmission electron microscopy; Porous membrane; Sol gel process; Preparation; Membrane; Experimental study; Composite material; Thermal stability; Titanium Oxides
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/S0272-8842(96)00072-7

A ceramic membrane consisting of an alpha-Al2O3 support and an Al2O3-TiO2 top layer, which is thermally stable up to 900 C, was prepared by the sol-gel method. The supported Al2O3-TiO2 top layer was made by dip-coating the support in a mixed sol. The microstructure of the composite membranes was studied by SEM and TEM after calcination at 850-1000 C. After sintering at 850 C for 1 h, the average particle diameter of the Al2O3-TiO2 top layer was about 15 nm. The supported Al2O3-TiO2 composite membranes exhibited much higher heat resistance than the TiO2 membranes. Although significant grain growth was observed for the TiO2 membrane after heating above 700 C due to phase transformation, the Al2O3-TiO2 composite membrane retained a crack-free microstructure and narrow particle size distribution even after calcination up to 900 C. 16 refs.