Fabrication of a Porous Bioactive Glass–Ceramic Using Room-Temperature Freeze Casting

The room-temperature freeze-casting method was used to fabricate porous bioactive glass–ceramics. In this method, a glass/camphene slurry prepared at 60°C was cast into a mold at 20°C, resulting in the production of a rigid green body that was comprised of three-dimensional dendritic camphene networks surrounded by highly concentrated glass powder walls. After the sublimation of camphene, the samples were sintered for 3 h at elevated temperatures ranging from 700° to 1100°C. As the sintering temperature was increased to 1000°C, the densification of the glass–ceramic wall was remarkably enhanced, while its highly porous structure was preserved. The sample sintered at 1000°C showed a high porosity of 53% and pore channels with a size of several tens of micrometers, as well as dense glass–ceramic walls. In addition, the fabricated samples effectively induced the deposition of apatite on their surfaces when immersed in simulated body fluid, implying that they are very bioactive.