Hierarchical porosity ceramic components from preceramic polymers

Cellular SiOC ceramic components with a porosity > 70 vol% and cell size dimension ranging from 10 μm to a few mm approximately have been developed using a silicone resin. These cellular materials have been further functionalized by developing a high specific surface area (SSA), which is useful for applications such as absorbers or catalyst supports. Several approaches were followed to achieve this goal, including controlling the heating process to retain the transient porosity, depositing a SiO 2-based meso-structured coating on the surface of the SiOC cellular material, or etching the foams in HF. The samples were characterized using various techniques, including SEM, high resolution and analytical TEM methods and N2 adsorption-desorption. The SSA value produced varied according to the processing strategy followed.