State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
J Colloid Interface Sci. 2010 Jan 1;341(1):18-22. doi: 10.1016/j.jcis.2009.09.017. Epub 2009 Sep 27.
Novel cubic nanocapsules consisting of metallic iron core and amorphous silica shell were fabricated through a simple chemical reduction route followed by a Stöber process. Thus-prepared Fe@SiO(2) nanocubes were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS), Fourier transform infrared spectrometer (FTIR), thermogravimetry-differential thermal analysis (TG-DTA), vibrating sample magnetometer (VSM) and scalar network analysis (SNA). Comparing with that of pure iron counterparts, silica-coated iron nanocubes exhibited improved magnetic properties, oxidation resistance and microwave absorption performance. A reflection loss (RL) exceeding -12 dB was obtained in the frequency range of 8-14 GHz for an absorber thickness of 2 mm, with an optimal RL of -18.2 dB at 9 GHz. Mechanism of the improved microwave absorption properties of the Fe@SiO(2) composite was discussed based on their magnetic properties and electromagnetic theory.
通过简单的化学还原法和 Stöber 工艺制备了由金属铁核和无定形二氧化硅壳组成的新型立方纳米胶囊。通过 X 射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、透射电子显微镜（TEM）、X 射线光电子能谱（XPS）、傅里叶变换红外光谱（FTIR）、热重-差热分析（TG-DTA）、振动样品磁强计（VSM）和标量网络分析（SNA）对制备的 Fe@SiO（2）纳米立方进行了表征。与纯铁相比，涂覆有二氧化硅的铁纳米立方表现出更好的磁性能、抗氧化性和微波吸收性能。对于厚度为 2mm 的吸收体，在 8-14GHz 的频率范围内获得了超过-12dB 的反射损耗（RL），在 9GHz 时达到了-18.2dB 的最佳 RL。基于其磁性能和电磁理论，讨论了 Fe@SiO（2）复合材料微波吸收性能提高的机制。
