Ammonium hydrogen carbonate provided viscous slurry foaming-A novel technology for the preparation of porous ceramics

In current research a novel technology for the preparation of porous ceramics was developed. The ammonium hydrogen carbonate was used as foaming agent for the generation of pores in the glycerol-based viscous ceramic slurry. Total and open porosity of obtained ceramics depends on the amount and granulometric distribution of NH4HCO3 as well as particle size of HAp powder used for the preparation of viscous slurry. Varying amount of NH4HCO3 in the range from 0 to 2.75 wt.%, open and total porosity increased from 25 to 69% and from 32 to 73% respectively. The formation of well-connected open porosity with irregularly shaped pores was observed for sintered ceramics.