Electromagnetic wave(EMW)absorbers with anti-corrosion property are highly desired to enhance the durability of military targets in harsh condition.Herein,cross-link NiAl-layered double hydroxide(NiAl-LDH)nanosheets o...Electromagnetic wave(EMW)absorbers with anti-corrosion property are highly desired to enhance the durability of military targets in harsh condition.Herein,cross-link NiAl-layered double hydroxide(NiAl-LDH)nanosheets on the inner/outer surfaces of carbon microtubes(CMTs)are ingeniously constructed through the combination of atomic layer deposition technique and a hydrothermal method.The obtained NiAl-LDH/CMT composite exhibits excellent EMW absorption and corrosion resistance performance.The large internal cavity of CMT significantly enhances impedance matching.The uniform distribution of NiAl-LDH nanosheets on both the inner and outer surfaces of CMT generates numerous heterogeneous inter-faces that induce substantial polarization loss.Consequently,at a filler rate of only 5 wt.%,the NiAl-LDH/CMT composite exhibits a minimum reflection loss of−60.2 dB and a maximum effective absorp-tion bandwidth of 5.9 GHz.In addition,the combined high impermeability of CMT and the effective Cl^(-)-trapping ability of NiAl-LDH endows NiAl-LDH/CMT composite with outstanding corrosion protection property in simulated seawater environment.Furthermore,the PO_(4)^(3-)anions are effectively incorporated into the NiAl-LDH interlayer via anion exchange,which can further enhance corrosion protection capac-ity through surface inactivation from slow-release PO_(4)^(3-)anions without reducing their EMW absorption performance.In summary,this work can give guidance for the development of efficient anti-corrosion EMW absorption materials.展开更多
Developing intelligent electromagnetic wave(EMW)absorption materials with real-time response-ability is of great significance in complex application environments.Herein,highly compressible Fe@CNFs@Co/C elastic aerogel...Developing intelligent electromagnetic wave(EMW)absorption materials with real-time response-ability is of great significance in complex application environments.Herein,highly compressible Fe@CNFs@Co/C elastic aerogels were assembled through the electrospinning method,achieving EMW absorption through pressure changes.By varying the pressure,the effective absorption bandwidth(EAB)of Fe@CNFs@Co/C elastic aerogels shows continuous changes from low frequency to high frequency.The EAB of Fe@CNFs@Co/C elastic aerogels is 14.4 GHz(3.36-17.76 GHz),which covers 90%of the range of S/C/X/Ku bands.The theoretical simulation indicates that the external pressure prompts a reduction in the spacing between the fiber layers in the aerogels and facilitates the formation of a 3D conductive network with enhanced attenuation ability of EMW.The uniform distribution of metal particles and appropriate layer spacing can effectively optimize the impedance matching to achieve the best EMW absorption performance.This work state clearly that the hierarchically assembled elastic aerogels composed of metal-organic frameworks(MOFs)derivatives and carbon fibers are ideal dynamic EMW absorption materials for intelligent EMW response.展开更多
Modulating the dipole polarization loss in the single-atom region and establishing its direct relationship with the electromagnetic wave absorption(EWA)performance remain an unmet challenge.Here,a dual-ligand modulati...Modulating the dipole polarization loss in the single-atom region and establishing its direct relationship with the electromagnetic wave absorption(EWA)performance remain an unmet challenge.Here,a dual-ligand modulation strategy,i.e.,partially changing coordination atoms in the single-metal region(sMr),is introduced to effectively break the coordination symmetry of conjugated metal-organic frameworks(cMOFs),finally enhancing EWA property of cMOFs materials.Further,the asymmetrical sMr is experimentally found to elicit the dipole polarization loss,overcoming the handicaps of other electromagnetic wave loss mechanisms,which directly contribution to enhance EWA performance of this series of cMOFs.This strategy is further confirmed by replacing metal centers.Among studied series of cMOFs,Cu_(2.25)/Co_(0.75)(HHTP1.67HITP0.33)achieves excellent EWA performance with an effective absorption bandwidth of 5.00 GHz and a reflection loss of66.03 dB.We introduce a dual-ligand modulation strategy targeting single-metal regions within cMOFs here,aiming to achieve superior EWA performance through atomic-scale dipole polarization loss modulation.We hope our study can inspire more exploration to realize high-performance EWA materials.展开更多
基金financially supported by the National Natu-ral Science Foundation of China(Nos.U24A20204,22168016,and 22278101)the Innovation Project for Scientific and Technological Talents in Hainan Province(No.KJRC2023C08)the Innovation Research Team in Hainan Province(No.525CXTD607).
文摘Electromagnetic wave(EMW)absorbers with anti-corrosion property are highly desired to enhance the durability of military targets in harsh condition.Herein,cross-link NiAl-layered double hydroxide(NiAl-LDH)nanosheets on the inner/outer surfaces of carbon microtubes(CMTs)are ingeniously constructed through the combination of atomic layer deposition technique and a hydrothermal method.The obtained NiAl-LDH/CMT composite exhibits excellent EMW absorption and corrosion resistance performance.The large internal cavity of CMT significantly enhances impedance matching.The uniform distribution of NiAl-LDH nanosheets on both the inner and outer surfaces of CMT generates numerous heterogeneous inter-faces that induce substantial polarization loss.Consequently,at a filler rate of only 5 wt.%,the NiAl-LDH/CMT composite exhibits a minimum reflection loss of−60.2 dB and a maximum effective absorp-tion bandwidth of 5.9 GHz.In addition,the combined high impermeability of CMT and the effective Cl^(-)-trapping ability of NiAl-LDH endows NiAl-LDH/CMT composite with outstanding corrosion protection property in simulated seawater environment.Furthermore,the PO_(4)^(3-)anions are effectively incorporated into the NiAl-LDH interlayer via anion exchange,which can further enhance corrosion protection capac-ity through surface inactivation from slow-release PO_(4)^(3-)anions without reducing their EMW absorption performance.In summary,this work can give guidance for the development of efficient anti-corrosion EMW absorption materials.
基金supported by the National Natural Science Foundation of China(Grant No.51772177)the Key Research and Development Program of Shaanxi Province(Grant No.2022GY-347).
文摘Developing intelligent electromagnetic wave(EMW)absorption materials with real-time response-ability is of great significance in complex application environments.Herein,highly compressible Fe@CNFs@Co/C elastic aerogels were assembled through the electrospinning method,achieving EMW absorption through pressure changes.By varying the pressure,the effective absorption bandwidth(EAB)of Fe@CNFs@Co/C elastic aerogels shows continuous changes from low frequency to high frequency.The EAB of Fe@CNFs@Co/C elastic aerogels is 14.4 GHz(3.36-17.76 GHz),which covers 90%of the range of S/C/X/Ku bands.The theoretical simulation indicates that the external pressure prompts a reduction in the spacing between the fiber layers in the aerogels and facilitates the formation of a 3D conductive network with enhanced attenuation ability of EMW.The uniform distribution of metal particles and appropriate layer spacing can effectively optimize the impedance matching to achieve the best EMW absorption performance.This work state clearly that the hierarchically assembled elastic aerogels composed of metal-organic frameworks(MOFs)derivatives and carbon fibers are ideal dynamic EMW absorption materials for intelligent EMW response.
基金supported by the National Natural Science Foundation of China(52172091,52172295)Defense Industrial Technology Development Program(JCKY2023605C002)+3 种基金Basic Research Program of Jiangsu(BK20232013)the National Key Laboratory on Electromagnetic Environmental Effects and Electro-optical Engineering(NO.61422062301)The Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0371,KYCX24_0571,KYCX25_0602)Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory(ZHD202305).
文摘Modulating the dipole polarization loss in the single-atom region and establishing its direct relationship with the electromagnetic wave absorption(EWA)performance remain an unmet challenge.Here,a dual-ligand modulation strategy,i.e.,partially changing coordination atoms in the single-metal region(sMr),is introduced to effectively break the coordination symmetry of conjugated metal-organic frameworks(cMOFs),finally enhancing EWA property of cMOFs materials.Further,the asymmetrical sMr is experimentally found to elicit the dipole polarization loss,overcoming the handicaps of other electromagnetic wave loss mechanisms,which directly contribution to enhance EWA performance of this series of cMOFs.This strategy is further confirmed by replacing metal centers.Among studied series of cMOFs,Cu_(2.25)/Co_(0.75)(HHTP1.67HITP0.33)achieves excellent EWA performance with an effective absorption bandwidth of 5.00 GHz and a reflection loss of66.03 dB.We introduce a dual-ligand modulation strategy targeting single-metal regions within cMOFs here,aiming to achieve superior EWA performance through atomic-scale dipole polarization loss modulation.We hope our study can inspire more exploration to realize high-performance EWA materials.
