Al₂O₃ porous ceramics with high strength by protein foaming method

This study explores a novel technique of preparing porous ceramics using egg white protein foaming method, in which hydrophobically modified Al₂O₃ particles self-assembly on the surface of protein bubbles to form a stable foam slurry, which is ultimately discharged and sintered to make porous Al₂O₃ ceramics. And egg white protein was a non-toxic and harmless natural substance that functions simultaneously as a foaming agent, a binder, and a gelling agent, has a significant advantage over ordinary foaming agents. The effect of protein foam content on the microscopic morphology, pore distribution, and strength of the porous ceramics was investigated. The mechanism of porous ceramics prepared by the protein foaming method was analyzed and the reliability of the study was verified by simulating the possible bonding with Gaussian 6.0. Porous ceramics with open porosity of 11.2-38.82%, near-spherical shape, average pore size of 150-240 μm, and compressive strength of 84-140 MPa were fabricated. The thermal insulating results showed that the porous ceramics have good thermal insulation performance, which was expected to be applied in the fields of aviation heat shields.