Ultralight lamellar amorphous carbon foam nanostructured by SiC nanowires for tunable electromagnetic wave absorption
Ultralight lamellar amorphous carbon foam nanostructured by SiC nanowires for tunable electromagnetic wave absorption
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DOI：
10.1016/j.carbon.2017.07.023
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发表时间：
2017-10
期刊：
影响因子：
10.9
通讯作者：
Shanshan Xiao;H. Mei;Daoyang Han;K. Dassios;Lai-fei Cheng
中科院分区：
文献类型：
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作者：
Shanshan Xiao;H. Mei;Daoyang Han;K. Dassios;Lai-fei Cheng
本文首次采用单向冷冻干燥和碳化技术相结合的方法合成了SiC纳米线与纳米结构层状碳膜复合的三维混杂泡沫材料。碳膜的结晶度可通过将所接收的混合泡沫热处理至600-1500 °C范围内的不同温度而从无定形碳调节至石墨烯样碳。SiC纳米线-纳米结构层状碳（SiC纳米线/C）混合泡沫表现出的电磁（EM）波吸收性能非常上级目前国家的最先进的同行，在填料负载低至9.2 mg/cm 3。观察到SiC纳米线/C泡沫的有效吸收带宽覆盖8.2-12.4 GHz的整个X波段频率范围，对于3.3 mm的最佳厚度，反射损耗值达到−31 dB。本文从所研制材料的高吸收层状结构、界面极化和多次反射效应以及极化弛豫效应等方面讨论了SiC NW/C混杂泡沫的吸收效率。
Three-dimensional hybrid foams of SiC nanowires (SiC NWs) coated and bonded with nanostructured lamellar carbon films are, herein synthesized for the first time, by combination of unidirectional freeze drying and carbonization techniques. The crystallinity of the carbon films was tunable from amorphous carbon to graphene-like carbon by heat treatment of the as-received hybrid foams to different temperatures within the range of 600–1500 °C. The SiC NWs-nanostructured lamellar carbon (SiC NWs/C) hybrid foams exhibited electromagnetic (EM) wave absorbing properties highly superior to current state-of-the-art counterparts, at filler loadings as low as 9.2 mg/cm3. Effective absorption bandwidth of the SiC NWs/C foam was observed to cover the whole X-band frequency range of 8.2–12.4 GHz, with reflection loss values reaching −31 dB for an optimum thickness of 3.3 mm. The absorption efficiency of the SiC NW/C hybrid foams is discussed in the text in view of the highly absorbing layered morphology of the developed material, of interfacial polarization and multiple reflections effects and of polarization relaxation effects.