Abstract
Freeze-casting is a solidificationMaterialsBiomaterials technique for fabricatingScaffoldsBiomaterials scaffolds with tunable micro-scale porous structures. In this chapter, the processing principles, theories, and experimental parameters of freeze casting technique are introduced. Two selected natural bio-ceramics, namely silica-based diatomite and fish scale-extracted hydroxyapatiteBiomaterials, are utilized as raw materials to fabricated scaffolds and composites. The intrinsic nano-porousBiomaterials features of diatomites are well preserved and integrated with the aligned micro-channels formed by ice dendrites during freezingMaterials. The hierarchical porous scaffolds exhibit ultra-lightweight, high porosity, superhydrophilicity and can be applied in the fields of filtration, water absorptionBioceramics and retention, oil–water separationBioceramics, and thermal insulationBioceramics. Fish scale-extracted hydroxyapatite scaffolds and composites are eco-friendlyBioceramics and cost-effective and can be heavy metal ion adsorption from wastewater and biomedical fields, such as bone grafting or dental materials. Future perspectives and applications of freeze casting technique are discussed.