Abstract:

Ultra-small CeO₂ nanoparticles uniformly embedded in carbon nanofibers (CeO₂@CNFs) composites were prepared by electrospinning and subsequent heat treatment. The effect and regulation mechanism of CeO₂ content on the electromagnetic characteristics and microwave absorption properties of CeO₂@CNFs were investigated in detail. It is found that with the increase of CeO₂ content, the dielectric loss and electromagnetic attenuation ability of the composites decreases while the impedance matching is effectively improved, and the microwave absorption ability first increases and then weakens. The CeO₂@CNFs-2 sample with a CeO₂ content of about 24.6%(mass) exhibits the best microwave absorption performance due to its better balance between electromagnetic attenuation and impedance matching. When the filler loading is only 10%(mass) in paraffin wax matrix and the absorber thickness is 3.0 mm, the minimum reflection loss (RL) of CeO₂@CNFs-2 reaches -45.4 dB at 10.7 GHz, and the effective absorption bandwidth (RL <-10 dB) is 5.6 GHz (9.1—14.6 GHz), covering approximately 75% of X-band and 45% of Ku-band. Notably, the microwave absorption intensity of CeO₂@CNFs-2 is 3.1 times that of pure CNFs, indicating that the synergistic effect of both CNFs and CeO₂ can effectively boost the microwave absorption performance of the composite.

Key words: CeO₂, carbon nanofibers, composites, nanostructure, microwave absorption

摘要：

采用静电纺丝结合后续热处理制备了均匀镶嵌超小CeO₂纳米颗粒的碳纳米纤维（CeO₂@CNFs）复合材料，研究了CeO₂含量对其电磁特性及吸波性能的影响和作用机制。结果表明，随CeO₂含量的增加，复合材料的介电损耗及电磁衰减能力降低，但阻抗匹配得到有效改善，吸波能力呈先增强后减弱趋势。CeO₂含量约为24.6%（质量）的CeO₂@CNFs-2样品因电磁衰减能力与阻抗匹配的更好平衡而表现出最好的吸波性能。当在石蜡基质中的填充量仅为10%（质量），厚度为3.0 mm时，最小反射损耗（RL）值达到-45.4 dB，RL低于-10 dB的有效吸收带宽为5.6 GHz （9.1~14.6 GHz），可覆盖约75%的X波段和45%的Ku波段。CeO₂@CNFs-2的吸波强度是纯CNFs的3.1倍，说明CNFs和CeO₂两者的协同作用能有效提高该复合体系的吸波性能。

关键词: CeO₂, 碳纳米纤维, 复合材料, 纳米结构, 微波吸收