Preparation of asymmetric perovskite-type membranes by a settlement method

Asymmetric SrCe(0.95)Yb(0.05)O(3-alpha) (SCYb) membranes were prepared by using a settlement method to deposit a thin dense SCYb layer on the green porous SCYb support, followed by conventional dry pressing and co-sintering. SCYb powder was mixed in a liquid media (isopropanol) and directly poured onto the pre-pressed green porous SCYb support placed in a beaker. After the powder fully settled onto the support, the green asymmetric sample was dried and co-sintered. The cross-sectional images of the asymmetric systems indicate that thin dense SCYb films in the asymmetric membranes had uniform thicknesses at this level of analysis and show excellent adhesion to the porous support without any undesirable defects, delamination or cracking. Further, different dense layer thicknesses (80-20 mu m) were readily obtained by altering the amount of the SCYb powders in the liquid media. The minimum dense layer thickness obtained by the settlement method, with the synthesis conditions utilised in this study, was around 20 mu m. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.