Investigation on Formation Mechanism of Magnetic Nanoparticles-Coated on Polystyrene Microspheres in Aqueous Solution of Anhydrous Ethylenediamine and Hexamethylenetetramine

In the past decades, there is a growing interest in the design and synthesis of composite microspheres with a dielectric solid sphere (e.g., silica, polystyrene) covered by metallic and their corresponding metal oxides shell, such as copper[1], gold[2], silver[3,4], iron oxide[5], zinc oxide[6,7], titanium oxide[8,9] and zirconium dioxide[10]. Such materials may exhibit a few unique electrical, optical, magnetic, catalytic, well-dispersed, or mechanical properties comparing to the traditional isotropic spherical microspheres. Iron oxide, which is a typical super paramagnetic material possessing a cubic inverse spinel structure, has been widely investigated due to their potential applications such as catalysts[11], photonics[12], separation and purification of bio-molecules, MRI contrast agent, hyperthermia, biosensor, and tar1College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 210009, PR China 2Department of Chemistry, Tonghua Normal College, Tonghua 134002, PR China