Modified chemical coprecipitation of magnetic magnetite nanoparticles using linear–dendritic copolymers

In this investigation, magnetite nanoparticles (Fe₃O₄ NPs) with a diameter of 5–10 nm were synthesized by coprecipitation from an alkaline solution of ferrous/ferric mixed salt-solution in the presence of copolymers. In this process, linear–dendritic copolymers containing a linear poly (ethylene glycol) core and dendritic poly (citric acid) arms were used as the stabilizer. The Fe₃O₄ NPs were characterized by transmission electron microscopy, energy-dispersive spectra, X-ray powder diffraction, field emission scanning electron microscopy, Fourier transform infrared spectrometer, and vibrating sample magnetometer. Compared to classical coprecipitation, the results showed that uniform, ultrafine, nearly spherical, and high purity nano-magnetite particles with better magnetic properties could be prepared by this method.

本研究中，研究者在共聚物存在条件下，通过共沉淀法从亚铁/铁混合盐的碱性溶液中合成了直径为5~10 nm的磁铁矿纳米颗粒（Fe₃O₄ NPs）。本次合成采用以线性聚乙二醇（poly(ethylene glycol)）为核、树状聚柠檬酸（poly(citric acid)）为臂的线性-树状共聚物作为稳定剂。通过透射电子显微镜（transmission electron microscopy）、能量色散谱（energy-dispersive spectra）、X射线粉末衍射（X-ray powder diffraction）、场发射扫描电子显微镜（field emission scanning electron microscopy）、傅里叶变换红外光谱仪（Fourier transform infrared spectrometer）及振动样品磁强计（vibrating sample magnetometer）对所制备的Fe₃O₄ NPs进行了表征。与传统共沉淀法相比，实验结果表明，该方法可制备出形貌均匀、超细微、近球形、高纯度且磁性能更优异的纳米磁铁矿颗粒。