Freeze Granulation of nanopowders
Freeze granulation gives the possibility to granulate nanoparticles, like graphene platelets and graphene oxide, achieving granules with high degree of homogeneity which are easily re-dispersed (if applicable) in a liquid or dis-integrated at a pressing operation. This is owing to the soft drying process giving week inter-particle bonding compare to what is obtained in conventional drying. Consequently, the nanosized material properties will be preserved, i.e. nano will still be nano. Freeze-drying of granules also prevents oxidation of metals or non-oxide materials as conventional drying does not, especially critical for nanopowders.
Nanoparticles can be granulated and dried into a powder and then re-dispersed to nanoparticles again avoiding agglomeration (aggregates), which is not possible with other granulation methods like spray drying.