Fe3O4/木质素基纳米碳纤维复合材料的制备及其微波吸收性能探究

Preparation of Fe3O4/ Lignin-based Carbon Nanofibers Composite and Its Microwave Absorption Performances

关键词:  木质素  中空  纳米碳纤维复合材料  微波吸收

Key Words:lignin  hollow  carbon nanofibers composite  microwave absorption

摘要:本研究以蔗渣乙酸木质素为原料制备了木质素基实心和中空纳米碳纤维（CNFs和HCNFs），然后采用溶剂热法，将经浓硝酸表面氧化处理后的碳纤维和乙酰丙酮铁共混反应合成了Fe₃O₄/实心和中空纳米碳纤维复合材料（Fe₃O₄/CNFs和Fe₃O₄/HCNFs）。通过傅里叶变换红外光谱仪和拉曼光谱仪分析了碳纤维在浓硝酸氧化处理前后的结构变化，通过扫描电子显微镜能谱仪、X射线衍射仪、比表面积孔径分析仪、振动样品磁强计和矢量网络仪分析并对比了Fe₃O₄/CNFs和Fe₃O₄/HCNFs的形貌结构、磁性能和微波吸收性能。结果表明，Fe₃O₄/CNFs和Fe₃O₄/HCNFs的饱和磁化强度分别为12.7 emu/g和16.5 emu/g，均表现出了典型的超顺磁性。相较于Fe₃O₄/CNFs，Fe₃O₄/HCNFs在厚度仅为1.5 mm下其最小反射损耗达-11.8 dB，另外随着吸波体厚度在1.0~2.5 mm范围变化，小于-10 dB的吸收频带范围为5.28 ~ 14.75 GHz，表现出了更优异的微波吸收性能。

Abstract:In this study, lignin-based solid and hollow carbon nanofibers (CNFs and HCNFs) were prepared from bagasse acetic acid lignin. The resultant CNFs and HCNFs were oxidized by nitric acid and then blended with ferric acetylacetonate to synthesize Fe₃O₄/CNFs and Fe₃O₄/HCNFs composite via a solvothermal method. The structure changes of CNFs and HCNFs before and after nitric acid oxidation treatment were analyzed by Fourier transform infrared and Raman spectrometers. The differences in morphological structure, magnetic property and microwave absorption performance between Fe₃O₄/CNFs and Fe₃O₄/HCNFs were compared by Scanning electron microscope-energy dispersive spectrometer, X-ray diffractometer, specific surface and porosity analyzer, vibrating sample magnetometer and vector network analyzer. The results showed that both Fe₃O₄/CNFs and Fe₃O₄/HCNFs had the typical superparamagnetism with the saturation magnetization values of 12.7 emu/g and 16.5 emu/g, respectively. The microwave absorption properties of Fe₃O₄/HCNFs were better than that of Fe₃O₄/CNFs. The minimum reflection loss of Fe₃O₄/HCNFs was up to -11.8 dB with a thickness of only 1.5 mm, and the reflection loss values less than -10 dB were obtained in the frequency of 5.28~14.75 GHz with thickness of 1.0~2.5 mm.