Cafer Yavuz

Nano Rust: Eco-friendly Magnetic Iron Oxide (Fe3o4) Nanocrystals Cafer Yavuz

This work describes the first size dependent magneticseparation in nanoscale by using rust like iron oxide. Magnetite (Fe3O4) nanocrystals of high quality and uniform size (4 nm to 33 nm) were synthesized. Batch synthesis was shown to go up to 20 grams which is more than 10 times of a standard nanocrystal synthesis, without loosing the quality and monodispersity. Reactor design for mass (1 gram per hour) production of magnetite nanocrystals isreported for the first time. A green synthesis thatutilizes rust and edible oils was developed. The costof a kg of magnetite nanocrystals was brought downfrom $2600 to $22. Size dependency of magnetism wasshown in nanoscale for the first time. Reversibleaggregation theory was developed to explain the lowfield magnetic separation and solution behavior ofmagnetite nanocrystals. Arsenic was removed fromdrinking water with magnetite nanocrystals 200 timesbetter than commercial adsorbents. Silica coating wassuccessfully applied and magnetite - silicananoshells were functionalized with amino groups. Forthe first time, silver was coated on the magnetite -silica nanoshells to produce triple multishells.