Nanotechnology has been evolving in the past decades as an alternative to conventional
fertilizers. Ferrihydrite nanoparticles that model the available Fe pool of soils
are proposed to be used to recover Fe deficiency of plants. Nevertheless, ferrihydrite
aqueous suspensions are known to undergo slow transformation to a mixture of goethite
and hematite, which may influence its biological availability. Several nanocolloid
suspensions differing in the surfactant type were prepared for plant treatment and
fully characterized by transmission electron microscopy and 57Fe Mössbauer spectroscopy
supported by magnetic measurements. The rate of transformation and the final mineral
composition were revealed for all the applied surfactants. Nanomaterials at different
stages of transformations were the subject of plant physiological experiments aiming
at comparing the behavior and plant accessibility of the manufactured suspensions
of nanoscale iron(III) oxide and oxide–hydroxide particles.
