Effects of rheological properties on ice-templated porous hydroxyapatite ceramics

Freeze casting of aqueous suspension was investigated as a method for fabricating hydroxyapatite (HA) porous ceramics with lamellar structures. The rheological properties of HA suspensions employed in the ice-templated process were investigated systematically. Well aligned lamellar pores and dense ceramic walls were obtained successfully in HA porous ceramics with the porosity of 68–81% and compressive strength of 0.9–2.4 MPa. The results exhibited a strong correlation between the rheological properties of the employed suspensions and the morphology and mechanical properties of ice-templated porous HA ceramics, in terms of lamellar pore characteristics, porosities and compressive strengths. The ability to produce aligned pores and achieve the manipulation of porous HA microstructures by controlling the rheological parameters were demonstrated, revealing the potential of the ice-templated method for the fabrication of HA scaffolds in biomedical applications.

► Systematical characterizations on HA suspensions' rheological properties.
► Well aligned lamellae pores obtained by ice-templated process.
► Porosity can be adjusted in the range of 68–81 vol.%.
► Compressive strength can be manipulated in the range of 0.9–2.4 MPa.
► Rheological properties showed strong influence on the porous HA ceramic.