A facile approach for transferring hydrophobic magnetic nanoparticles into water-soluble particles

A novel, easy and high-efficient method is described for transferring hydrophobic magnetic Fe3O4 nanoparticles from organic to aqueous solution by wrapping a thermo-responsive and photocrosslinkable poly(N-isopropylacrylamide) (PNIPAm) terpolymer around the particles. The wrapping procedure is introduced by the co-nonsolvent transition of PNIPAm in the mixing solvent and the polymer can dissolve in water carrying Fe3O4 nanoparticles by noncovalent interaction. The temperature-dependant and magnetic properties of the water-soluble particles are characterized in this paper.