包覆油酸的Fe_3O_4纳米粒子的制备

Preparation of Magnetite Particles Coated with Oleic Acid

用FeSO4和FeCl3在氨水和油酸作用下,共沉淀制备了包覆油酸的Fe3O4纳米粒子,考察了沉淀温度、油酸加入前反应时间及总铁离子浓度对其粒径的影响.结果显示,沉淀温度的升高和油酸加入前反应时间的延长,均可使Fe3O4粒径增大.沉淀温度从20℃增加到80℃,粒径从大约5nm增加到8nm;油酸加入前反应时间从10min延长到30min,粒径从大约3nm增加到8nm.c（总铁离子）=0.1～1.1mol/L时对粒径没有显著影响,Fe3O4粒径均为8nm左右,c（总铁离子）＞1.1mol/L时,粒径明显减小.

Magnetite particles of different diameters coated with oleic acid were prepared by coprecipitation of FeSO4and FeCl3 with ammonia and then addition of oleic acid. The influences of precipitation temperature, the reaction time before adding oleic acid and the concentrations of iron ions on particle diameter were studied. The results demonstrated that both the elevation of precipitation temperature and prolonging of the reaction time before adding oleic acid could increase the diameter of magnetite particles. By elevation of precipitation temperature from 20 ℃ to 80 ℃, the particle diameter increased from about 5 nm to 8 nm. When the reaction time before adding oleic acid was prolonged from 10 min to 30 min ,the particle diameter increased from about 3 nm to 8 nIn. Meanwhile, it showed no influence on particle diameter when the concentrations of iron ions were in the range of 0. 1 - 1.1 mol/ L, and the particle diameter was about 8 nm, while the particle diameter decreased sharply when the concentration of iron ions exceeded 1.1 mol/L.