Sedimentation of Fe2O3 and metallic iron nanoparticles exhibiting Brownian movement

Sedimentation of nanoparticles in water solutions was studied in situ by transmission Mössbauer spectroscopy in horizontal and vertical geometry. The studied specimens were Fe2O3 of a commercial pigment and metallic iron nanoparticles in slurry used in a water purification technology. The sedimentation is selective and leads to the gradual removing of the bigger particles from a solution. The iron nanoparticles in the solution are relatively chemically stable until, due to the drying, the sediment becomes exposed to the air.