SiCN ceramics with controllable carbon nanomaterials for electromagnetic absorption performance |
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| Authors: | Yuyu Zhang Jia Sun Yuqi Wang Ralf Riedel Qiangang Fu |
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| Affiliation: | 1. State Key Laboratory of Solidification Processing, Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials, Carbon/Carbon Composite Research Center, Northwestern Polytechnical University, Xi’an, P. R. China;2. Institut für Materialwissenschaft, Technische Universität Darmstadt, Darmstadt, Germany |
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| Abstract: | Different kinds of carbon nanomaterials, free carbon (Cfree), graphene, and N-containing graphene (NG), in single-source-precursors-derived SiCN ceramics, were in situ generated by modifying polysilazane with divinylbenzene, dopamine hydrochloride and melamine, respectively. Adjusting the carbon source brings phase structure and electromagnetic wave absorption (EMA) properties differences of SiCN/C ceramics. In situ Cfree enhances the EMA capacity of SiCN ceramics by improving their electrical conductivity of 9.2 × 10?4 S/cm. The electrical conductivity of SiCN ceramics with 2D graphene sheets balloons to 2.5 × 10?3 S/cm, causing poor impedance match thus leading to a worse EMA performance. In situ NG in SiCN ceramics has a low electrical conductivity of 5.6 × 10?8 S/cm, making for excellent impedance match. The corrugated NG boosts dielectric loss, interfacial, and dipole polarization. NG-SiCN nanocomposites possess an outstanding EMA performance with RLmin of ?61.08 dB and effective absorption bandwidth of 4.05 GHz, which are ～2.4 times lower and ～4 times higher than those of SiCN, respectively. |
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| Keywords: | carbon electromagnetic properties graphene silicon carbonitride |
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