Abstract: The present invention relates to a process for modifying the dispersing properties of organometallic-prestabilized or organometallic-pretreated nanometal colloids by reacting reactive metal-carbon bonds in the protective shell to prepare nanometal colloids having a wide range of solubilities in hydrophilic and hydrophobic media including water, to the colloids thus prepared and their use.

Abstract: The invention relates to new single- or multi-metallic magnetic colloid particles (for example, Fe, Co, Ni, Fe/Co) having a size of up to 20 nm, the surface of which is protected against corrosion by precious metals, such as Pd, Ag, Pt or Au. The invention also relates to a method for producing such materials. In isolated form or in solution said materials are used among other things as sealing media against dust and gas in magnetic fluid seals (liquid O ring), for lubricating and mounting rotating shafts (magnetic levitation bearing), for the magnetooptic storage of information as well as for the magnetic marking of cells and their separation in biological samples or for the local administration of medicines.