The magnetic properties of iron oxide based nanoparticles can be controlled by wet-chemically tailoring their size, shape and composition.[1,2,3]
Among the different magnetic properties which can be obtained, focus in this talk will be on superparamagnetic nanoparticles. This property turns them into nano objects, which are switchable in their magnetic properties by an external field.
These nanoparticles are used as building-blocks to create more complex particle architectures, namely so-called supraparticles. New functionalities may emerge from these supraparticles either due to the colocalization of multiple building-block components or due to a particular structural arrangement of one type of building-block.
Three types of superparamagnetic nanoparticle-building-block based supraparticles will be presented:
1) Multicomponent supraparticles that act as carrier particles in fluids. With these, unwanted or valuable substances were concentrated in fluids, collected, removed and recovered.[4-7] Moreover, such particles may act as detectors.
2) Single component hollow iron oxide nanoparticle based microballoon supraparticles which are ultralightweight.
3) Anisotropic rod-like supraparticle sutrctures which yield unexpected optical properties.
These examples shall demonstrate the potential of wet-chemical assembly of magnetic supraparticle architectures towards novel functionalities.
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