Material Synthesis using Freeze Granulation
Freeze granulation is an excellent tool for precursor preparation in material synthesis. Soluble or non-soluble compounds are initially mixed in water or a suitable organic solvent, optionally by mechanical treatment such as ball milling. The homogeneous solution/suspension is then freeze granulated with preserved homogeneity in the dried granules ensuring a high yield of desired material composition after the subsequent thermal treatment (calcination). The only restriction regarding solvent and precursor composition is that the resulting freezing point of the solution/suspension cannot be lower than about -20°C to avoid melting during the freeze drying operation. As freeze granulation provides granules with comparably low density, it will also be easier to disintegrate the calcined material into the desired size compared to what can be expected when conventional drying of the precursor mix has been used in the preparation step.