This study discusses the impact of colloidal suspension properties on the wet foam stability of porous ceramics obtained by direct foaming from a particle-stabilized colloidal suspension. The influence of binder content on the wet foam stability in terms of rheology, surface tension, average bubble size and air content are reported. The partial hydrophobization of colloidal suspension was carried out by applying Octylamine as surfactant. PEG binder was added as a wet foam stabilizer. The results shows the wet foam stability of more than 90%, which corresponds to an air content of 86.5% with a colloidal suspension containing 20 wt.% of binder. The Newtonian additive, binder decreases viscosity of colloidal suspension to create a favorable condition for wet foam stability. Uniform distribution of highly open/interconnected pores was controlled with an increase in the binder content of up to 20 wt.%, leading to a higher wet foam stability for porous ceramics.

Keywords: Colloidal suspension, Rheology, Direct foaming, Wet-foam stability, Porous ceramics