High-porosity geopolymer membrane supports by peroxide route with the addition of egg white as surfactant

Metakaolin-based geopolymer membrane supports were synthesized by gelcasting using hydrogen peroxide with the addition of albumen powder as surfactant. A geopolymer slurry was prepared using metakaolin and an alkaline medium at room temperature, the obtained viscous paste was expanded by means of the decomposition of peroxide in combination with protein-assisted foaming, and the geopolymerization was conducted in a closed environment at 75 °C. The combination of peroxide and albumen protein enabled the production of geopolymer membrane supports with a total porosity of ~74.29%, open porosity as high as ~65.25%, and possessing a compressive strength of ~4.47 MPa. Moreover, factors that influence the compressive strength, the porosity, and the pore size distribution were investigated. The results showed that the sizes of cell could be controlled by adding different content of peroxide and protein, and by heat-treating at different temperatures.