Controlling the Structure of Hydroxyapatite Ceramics with Dual Pores Prepared Using Freeze-Casting

A hydrogen peroxide solution in deionized water was used as the pore-forming agent in freeze-casting to fabricate a hydroxyapatite porous ceramic containing both lamellar and spherical macrospores. The influence of the volumetric content of H2O2 in the mixed solvent on the morphology of the porous ceramic was analyzed, and the effect of the solvent cooling speed on the microstructure and pore morphology of the pore ceramic was also investigated. The results show that H2O as the sole pore-forming agent led to the formation of a HA scaffold with only lamellar pores. When 3% (v/v) of H2O2 solution was used, both lamellar and spherical pores were observed. However, when the concentration of H2O2 reached 9% (v/v), only spherical pores were formed in the porous ceramic. The average lamellar spacing and the spherical pore size of the pore ceramic composed of HA decreased with the increase of the cooling speed.