Chemical Dynamics of Monodispersed Iron Oxide Nanoparticles

This study is comprised of the synthesis and characterization of uniform fine particles of iron oxide in different shapes and sizes. Varying amounts of iron (III) chloride and sodium dihydrogen phosphate was heated at 98 oC for various periods, following the forced hydrolysis method. Scanning electron microscopic analysis showed that the shape and size of the precipitated particles were dependent on the applied experimental conditions. Selected batches of the synthesized particles were characterized by various physical methods i.e., XRD, FT-IR, electrophoretic mobility to confirm their identity. The high concentration of phosphate ions tended the particles to grow lengthwise so as the morphology of the precipitated particles change from spherical (axial ratio 1) to ellipsoidal (axial ratio 6) shape. The excess amount of ferric chloride in the reaction, medium facilitated the growth of the primarily formed particles. The particle size increased with aging and attained a limiting value in 94 h. All the solids were crystalline and the observed peaks in the XRD patterns corresponded to iron (III) oxide. These findings are important in developing a facile and robust method for the synthesis of monodispersed particles of various metal oxides and controlling their size and shape.