Preparation and properties of the hierarchical structural porous ceramics constructed by alumina interlocking matrix and silicon carbide nanowire aerogel filler

Pore-structure-tailorable composites were constructed by alumina platelets' interlocking matrices and self-assembled SiC nanowire aerogels. The nanowires grew in the unidirectional pores of the matrices with the silica-based xerogel that filled in the pores or covered on the platelets as nucleation base. Nanowire aerogels as secondary structure built by curly or long/straight nanowires formed with changing the Si/C mole ratio (1/3∼1/12) and sintering temperature (1300–1500 °C). The tested composites had relatively close bulk densities, porosities and pore volumes of 0.66–0.76 g/cm 3 , 81.6–77.8 % and 1.04–1.25 mL/g respectively. The specific surface areas of the composites with regulable pore size distributions were tailored in the range of 2.43–9.05 m 2 /g. The nanowires acted as “lotus root silk”-like adhesion structure during/after the compression to restrain the catastrophic damage of the material. The synthesized composites with adjustable pore-structure and remarkable using reliability were suitable for hot gas filtration, catalyst supporting, or dye/oil adsorption in waste water, etc.