Alginate-templated synthesis of CoFe/carbon fiber composite and the effect of hierarchically porous structure on electromagnetic wave absorption performance
Alginate-templated synthesis of CoFe/carbon fiber composite and the effect of hierarchically porous structure on electromagnetic wave absorption performance
复制标题
海藻酸盐模板合成CoFe/碳纤维复合材料及分级多孔结构对电磁波吸收性能的影响
DOI：
10.1016/j.carbon.2019.05.025
复制
发表时间：
2019-10-01
期刊：
影响因子：
10.9
通讯作者：
Shui, Jianglan
中科院分区：
文献类型：
--
作者：
Song, Zhiming;Liu, Xiaofang;Shui, Jianglan
以天然海藻酸纤维为模板制备了CoFe合金修饰的层状多孔碳纤维(HPCF)。由于与带负电荷的α-L-古鲁酸盐嵌段配位，过渡金属(TM)离子可以被限制在海藻酸盐的“蛋盒”结构中，在碳化过程中转化为均匀嵌入到高性能碳纤维中的CoFe合金颗粒。通过调节吸附的Tm离子和碳化温度，可以很好地控制磁性粒子的组成和重量比。与以往具有均匀介孔的类似物不同，这种复合纤维同时具有多个中孔和高比例的亚微米大孔，这不仅有利于大尺寸CoFe颗粒的容纳，而且还导致了丰富的界面极化和EMW多次散射。值得注意的是，填充质量分数低至15wt%的CoFe/HPCF在1.6 mm的厚度处获得了-69.1分贝的极强反射损耗，其有效吸收带宽达到5.2 GHz，综合性能优于其他同类吸波材料。这项工作突出了分层多孔结构(特别是大孔结构)在改善EMW吸收方面的重要性。该合成策略具有绿色、低成本、可扩展等特点，可用于合成其他高效复合吸波材料。(C)2019爱思唯尔有限公司。保留所有权利。
Natural alginate fibers are used as templates to fabricate CoFe alloy-decorated hierarchically porous carbon fibers (HPCFs). Due to the coordination with negatively charged alpha-L-guluronate blocks, transition metal (TM) ions could be confined in the "egg box" structure of alginate, which convert to CoFe alloy particles that homogenously embedded in HPCFs during carbonization. The composition and weight ratio of magnetic particles could be well controlled by adjusting the absorbed TM ions and carbonization temperature. Unlike previous analogues with uniform mesopores, this composite fiber simultaneously possesses a number of mesopores and a high proportion of submicron macropores which not only facilitates the accommodation of large-sized CoFe particles, but also induces abundant interfacial polarization and EMW multi-scattering. Remarkably, the CoFe/HPCF with a filler loading as low as 15 wt% in matrix achieves an extremely strong reflection loss of -69.1 dB at a thin thickness of 1.6 mm, and its effective absorption bandwidth reaches 5.2 GHz, showing better comprehensive properties than other similar absorbers. This work highlights the importance of hierarchically porous structure (especially macroporous structure) on improving EMW absorption. The synthetic strategy is green, low cost, scalable, and can be used to synthesize other highly efficient composite absorbers. (C) 2019 Elsevier Ltd. All rights reserved.