• Porous mullite ceramic used in a wide range of applications such as high temperature insulation, filter membrane for highly corrosive and high-pressure environments.
• However, the functional properties desirable for a given application is highly dependent on the composition and microstructure of the porous network, which in turn depends on the processing technique which described lengthy inefficient processing method and inefficient properties of particles as final ceramic.
• Hence, there is a need of improved method to overcome above issues.

Present invention describes a method for preparing porous mullite ceramic from Pickering emulsions stabilized by hetero aggregate of oppositely charged fumed oxide particles.

• The pore size of final ceramic structure is controlled by tuning the emulsion droplet size wherein the droplet size largely depends on the mixing fraction of the particles, aqueous phase pH and the homogenization speed which eventually control the pore size in the final ceramic.
• The porous ceramic is prepared by drying and sintering of emulsion get stabilized by oppositely charged particles.

The method comprises steps mentioned in below:

1. Using oppositely charged fumed oxide particles to stabilize oil-in-water Pickering emulsions, wherein the volume ratio of oil phase to aqueous phase fixed at 1:1.
2. Using Pickering emulsions template that is formulated with fumed oxide nano particles (silica & alumina) to produce green body which is transformed into solid porous material with a controlled porosity and pore size by sintering.
3. Emulsifying the resulting sample consisting of oil and aqueous phases with a homogenizer (IKA T25 ULTRA TURRAX) at 13000rpm for 3 min.