P17 超音波/逆沈殿法による超常磁性酸化鉄ナノ粒子の調製(ポスター発表)

抄録

Magnetic iron oxide nanoparticles were successfully prepared by a novel reverse precipitation method with the irradiation of ultrasound. TEM, XRD and SQUID analyses showed that the formed particles were magnetite (Fe_3O_4) with about 10 nm in their diameter and that the magnetite nanoparticles exhibited superparamagnetism above about 200 K. The sizes and size distributions could be controlled by the feeding conditions of FeSO_4・7H_2O aqueous solution, and slower feeding rate and lower concentration lead to smaller and more uniform magnetite nanoparticles. The mechanisms of sonochemical oxidation were also discussed. The analyses of sonochemically produced oxidants in the presence of various gases suggested that nitrite and nitrate ions, besides sonochemically formed hydrogen peroxide, contributed to Fe(II) ion oxidation.