Freeze casting - ice templating

The potential field of application of porous ceramics is increasing; the porosity is a functional property, so that 3D porous ceramics with interconnected and distributed open pores are designed for the specific application. Water-based freeze casting, "ice-templating", is a novel technique to fabricate porous ceramic 3D structures with main unidirectional oriented pores, a high open porosity and the final components resulting in a lamellar or laminate-like structure. In details, the final porosity network resembles the ice crystals grown during freezing and eliminated by sublimation, thus it can be tuned acting on several parameters, in particular the water content of the slurry and the freezing direction and kinetics. The process is environmentally friendly (compared to other templating methods that use non aqueous medium or polymeric templates, which need to be burned out) and highly versatile. This technique has seen great interest, in particular for the unique structures and properties showed by porous freeze-cast ceramics, which open new opportunities in the field of cellular ceramics. ISTEC designs, produces and characterizes lab scale prototypes. ISTEC has developed freeze-cast ceramics as bioceramics, UHTC based solar sorbents (CNR Patent MI2012A000583) and ceramics for catalysis and filtration.