Fabrication and Characterization of Biphasic Calcium Phosphate Scaffolds with an Unidirectional Macropore Structure Using Tertiary-Butyl Alcohol-Based Freeze-Gel Casting Method

Porous biphasic calcium phosphate scaffolds were fabricated by a freeze-gel casting technique using a tertiary-butyl alcohol (TBA)-based slurry. After sintering, unidirectional macropore channels of scaffolds aligned regularly along the TBA ice growth direction were tailored simultaneously with micropores formed in the outer wall of the pore channels. The crystallinity, micro structure, pore configuration, bulk density, and compressive strength for the scaffolds were investigated with X-ray diffractometery, scanning electron microscopy analysis, a water immersion method, and a universal test machine. The results revealed that the sintered porosity and pore size generally resulted in a high solid loading which resulted in low porosity and small pore size, which relatively increased the higher compressive strength. After being sintered at 1100-1300℃, the scaffolds showed an average porosity and compressive strength in the range 35.1-74.9% and 65.1-3.0 MPa, respectively, according to the processing conditions.