Microstructure and permeability of porous zirconia ceramic foams prepared via direct foaming with mixed surfactants

Abstract

The permeability performance of porous ceramics from particle-stabilized foams is closely associated with the connectivity between bubble-evolved pores. In order to regulate the connectivity of pore structure, the zirconia ceramic foams were fabricated by direct foaming with mixed surfactants of cetyltrimethyl ammonium bromide (CTAB) and sodium N-lauroyl sarcosinate (SLS). Different solid loadings and CTAB:SLS mixing ratios were used in this study. The results indicate that the pore structures of zirconia ceramic foams were interconnected by open windows on the cell walls, and the porosity and average size of cell and cell windows could be tailored by adjusting the solid loading and CTAB:SLS mixing ratio. The decrease in solid loading and CTAB:SLS mixing ratio caused larger porosity and size of cells and cell windows, and thus resulted in the obvious augment of Darcian (k1) and non-Darcian (k2) permeability constants. The ranges of k1 and k2 of the as-fabricated zirconia ceramic foams are 6.92 × 10−13-4.05 × 10−10m2 and 2.09 × 10−5-3.19 × 10−9m respectively.