Synthesis of magnetite submicrospheres with tunable size and superparamagnetism by a facile polyol process

Magnetite submicrospheres with an average size range of 90–490 nm were obtained by a facile polyol process. The effects of reaction conditions on the morphology and static magnetism of magnetite submicrospheres were studied when the reaction time, the concentration of component, and the types of the solvent or surfactant changed. The average size of primary crystals was controlled by changing the concentration of surfactant thus the superparamagnetism was obtained, meanwhile the average size of secondary clusters was tuned by changing the concentration of ferrous precursor FeCl3·6H2O. The ratio of ethylene glycol and diethylene glycol, the concentration of NaAC, and the reaction time all exhibited novel effects on the morphology of magnetite submicrospheres facilitating our understanding about the synthesis mechanism. The synthesized magnetite submicrospheres were successfully used for photonic crystal.

► Color tunable colloidal crystals were fabricated by a facile polyol process. ► The size of magnetite primary crystals was decreased using high [PAA]. ► Meanwhile the size of magnetite submicrospheres was tuned by changing [FeCl3·6H2O]. ► EG/DEG, [NaAC], and the reaction time all exhibited novel effects.