Microstructure control in ceramic foams via mixed cationic/anionic surfactant

Silica ceramic foams with controllable microstructure were produced by direct foaming method. The silica foams were prepared through three different systems: individual cationic surfactant stabilized system, individual anionic surfactant stabilized system, and the mixed cationic/anionic surfactant stabilized system. The foaming ability and foam stability of the three systems were investigated and the related mechanisms were discussed. The results showed that the mixed system had both long-term stability and good foaming ability compared with the others. In addition, the role of the anionic surfactant (SDS) on microstructure of the ceramic foams was studied. The results showed that the foam structure changed from closed pores to open pores with the increasing concentration of SDS. (C) 2012 Elsevier B.V. All rights reserved.