The X band(8 GHz-12 GHz)is the electromagnetic wave band emitted by most electronic instruments in our life,which will cause electromagnetic pollution harm to human health.Due to the coexistence of magnetic loss and d...The X band(8 GHz-12 GHz)is the electromagnetic wave band emitted by most electronic instruments in our life,which will cause electromagnetic pollution harm to human health.Due to the coexistence of magnetic loss and dielectric loss,the modified Fe_(3)O_(4)-carbon-based nanomaterial exhibit strong electromagnetic(EM)wave absorptive capacity.However,there is a problem that the effective absorption bandwidth(EAB,the frequency bandwidth of reflection loss is less than-10 dB)of the X band is narrow.Increasing the EAB value of Fe_(3)O_(4)-carbon-based materials is of great significance for reducing electromagnetic pollution.Here,an emulsion-based self-assembly technique and ligand carbonization treatment have been used to construct the Fe_(3)O_(4)@C supraparticles for the evaluation of EM performance.The Fe_(3)O_(4)@C supraparticles exhibit excellent EM absorption properties,which can achieve full coverage of X band from 6.52 GHz to 12.9 GHz at a sample thickness of 3 mm.Besides,the optimum EAB value of Fe_(3)O_(4)@C supraparticles is up to 8.55 GHz from 9 to 18 GHz at a sample thickness of 2.5 mm.The Fe_(3)O_(4)@C supraparticles with superlattice structure will have potential development prospects in the application of broadband absorption.展开更多
基金support from National Natural Science Foundation of China(No.51702046 and No.91963204)the program for Professor of Special Appointment(Eastern Scholar),State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University.
文摘The X band(8 GHz-12 GHz)is the electromagnetic wave band emitted by most electronic instruments in our life,which will cause electromagnetic pollution harm to human health.Due to the coexistence of magnetic loss and dielectric loss,the modified Fe_(3)O_(4)-carbon-based nanomaterial exhibit strong electromagnetic(EM)wave absorptive capacity.However,there is a problem that the effective absorption bandwidth(EAB,the frequency bandwidth of reflection loss is less than-10 dB)of the X band is narrow.Increasing the EAB value of Fe_(3)O_(4)-carbon-based materials is of great significance for reducing electromagnetic pollution.Here,an emulsion-based self-assembly technique and ligand carbonization treatment have been used to construct the Fe_(3)O_(4)@C supraparticles for the evaluation of EM performance.The Fe_(3)O_(4)@C supraparticles exhibit excellent EM absorption properties,which can achieve full coverage of X band from 6.52 GHz to 12.9 GHz at a sample thickness of 3 mm.Besides,the optimum EAB value of Fe_(3)O_(4)@C supraparticles is up to 8.55 GHz from 9 to 18 GHz at a sample thickness of 2.5 mm.The Fe_(3)O_(4)@C supraparticles with superlattice structure will have potential development prospects in the application of broadband absorption.
