Manipulation of chemically synthesized FePt nanoparticles in water:: Core-shell silica/FePt nanocomposites

A simple process to manipulate FePt nanoparticles in aqueous solution for controlling the FePt shell thickness on the silica spheres is described. FePt-fuctionalized silica particles with controlled core-shell morphology were synthesized using the layer-by-layer (LbL) sequential adsorption technique of polyelectrolytes. The deposition of water-based FePt nanoparticles onto silica spheres was accomplished through the LbL self-assembly technique of polyelectrolytes. FePt nanoparticles in water are stabilized by an electrostatic double layer. The electrostatic double layer will allow the manipulation of FePt nanoparticles in water, which helps in forming nanoparticulate films on silica spheres and core-shell structures. The core-shell spheres are used in various applications requiring high-performance, permanent-magnetic nanocomposites due to their unique magnetic properties.