【摘 要】
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Electromagnetic wave absorbing materials at high-temperature are urgently needed for stealth aircrafts or aero-engines worked in harsh environments.In this contribution,cobalt-containing siliconboron carbonitride (MOF/SiBCN) nanomaterials were prepared by
【机 构】
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MOE Key Laboratory of Material Physics and Chemistry under Extraordinary,Shaanxi Key Laboratory of M
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Electromagnetic wave absorbing materials at high-temperature are urgently needed for stealth aircrafts or aero-engines worked in harsh environments.In this contribution,cobalt-containing siliconboron carbonitride (MOF/SiBCN) nanomaterials were prepared by pyrolyzing metal-organic framework,i.e.cobalt 2-methylimidazole (ZIF-67),and hyperbranched polyborosi-lazane.The rhombic dodecahedral ZIF-67 and cobalt element promoted in situ formation of dielectric loss phases,including SiC nanocrystals,CoSi nanocrystals and turbostratic carbons.The ZIF-67/SiBCN nanomaterials showed excellent microwave absorption both at room and elevated temperature.The minimum reflection coefficient (RCmin) was-51.6 dB and effective absorption bandwidth (EAB) is 3.93 GHz at room temperature.At an elevated temperature of 600 ℃,the RCmin reached-30.29 dB and EAB covered almost the whole X-band (3.95 GHz,8.4512.4 GHz).The ZIF-67/SiBCN nanocomposites are promising and useful platform for micro-wave absorbing materials at high-temperature.It may shed light on the downstream applications in designing next generation areo-engines and stealth aircrafts.
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