撞击流反应器制备纳米四氧化三铁的研究

在浸没式循环撞击流反应器中，以氨水为沉淀剂，用七水合硫酸亚铁和六水合三氯化铁为原料，采用共沉淀法制备了纳米四氧化三铁粒子。考察了搅拌转速、亚铁与三价铁物质的量比、反应温度和溶液pH对所得纳米四氧化三铁的分散性和粒径的影响。采用傅里叶红外光谱仪、透射电镜、X射线衍射仪等对制得的纳米粒子的结构和性能进行了表征。结果表明：用撞击流反应器制备纳米四氧化三铁粒子的最佳工艺条件：亚铁与三价铁物质的量比为1 ∶1，反应温度为40 ℃，搅拌转速为1 600 r/min，以氨水作沉淀剂，最佳pH控制在11.0左右。在上述条件下，可以制备出分散性好、纯度高、平均粒径为10 nm的四氧化三铁粒子。

Preparation of Fe3O4 nanoparticles by impinging stream reactor

In submerged circulative impinging stream reactor,Fe₃O₄ nanoparticles were prepared by co-precipitation method,with FeSO₄?7H₂O and FeCl₃?6H₂O as raw materials,and ammonia as precipitator.Effects of stirring rate,amount-of-substance ratio of Fe²⁺ to Fe³⁺,reaction temperature,and pH on dispersion and particle size of Fe₃O₄ nanoparticles were investigated.Structure and performance of Fe₃O₄ nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR),transmission electron microscopy (TEM),and X-ray diffraction (XRD).Results showed that Fe₃O₄ nanoparticles with good dispersion,high purity,and mean particle size of 10 nm could be prepared under following optimum technological conditions:amount-of-substance ratio of Fe²⁺ to Fe³⁺ was 1 ∶1,reaction temperature was 40 ℃,stirring rate was1 600 r/min,pH was about 11.0 in the presence of ammonia as precipitant.