MXene is considered as a candidate for preparing high-performance electromagnetic wave absorbing materials due to its large specific surface area,rich surface modification groups,and unique metal properties.However,th...MXene is considered as a candidate for preparing high-performance electromagnetic wave absorbing materials due to its large specific surface area,rich surface modification groups,and unique metal properties.However,the impedance matching problem caused by its high conductivity and easy stacking properties is a limiting factor.In this study,a self-assembling-etching-anchoring growth method was proposed to prepare MXene@Co electromagnetic wave absorbing materials.The hollow structure of MXene microspheres constructed with PMMA as a hard template is conducive to optimizing impedance matching and surface modification.In addition,MXene@Co exhibits abundant heterogeneous interfaces,enhancing the interfacial polarization phenomenon during electromagnetic wave absorption.Meanwhile,the surfaceanchored growth of magnetic Co particles forms a magnetic network,which provides a strong magnetic loss capability for the absorber.The hollow structure design significantly enhances the wave absorption performance compared to conventional MXene@Co composites,with a minimum reflection loss of−57.32 dB(effective absorption bandwidth of 5.2 GHz)when the thickness is 2.5 mm(2.2 mm).This work provides a meaningful reference for the design of MXene-based electromagnetic wave absorbing materials.展开更多
A series of silicates with double shell hollow sphere morphology were prepared by hydrothermal method with ultra-high temperature calcined,and used in the field of electromagnetic(EM)wave absorption.By characterizing ...A series of silicates with double shell hollow sphere morphology were prepared by hydrothermal method with ultra-high temperature calcined,and used in the field of electromagnetic(EM)wave absorption.By characterizing the chemical composition,crystal structure,micro morphology and EM parameters of the several materials,the evaluation results of EM wave absorption capacity of the materials were obtained.In the discussion section,we will discuss the reasons for the differences in EM wave absorption capabilities of the several silicates from multiple aspects such as EM wave absorption mechanism in detail.Especially for iron-based silicate(HGMs@Fe_(2)SiO_(4))materials,after reasonable composition and morphology design,the minimum reflection loss(RLmin)reached up to-41.14 d B with a matching thickness(d)of 3.4 mm,and the corresponding effective absorption bandwidth(f_(E),RL<-10 d B)was 6.80 GHz.Because of the wide EM wave absorption bandwidth,light weight and low water absorption,this kind of double shell silicate material has gained huge application potential in the EM wave absorption field.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51407134,52377026 and 52301192)the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)+2 种基金the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)Special Financial of Shandong Province(Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams).
文摘MXene is considered as a candidate for preparing high-performance electromagnetic wave absorbing materials due to its large specific surface area,rich surface modification groups,and unique metal properties.However,the impedance matching problem caused by its high conductivity and easy stacking properties is a limiting factor.In this study,a self-assembling-etching-anchoring growth method was proposed to prepare MXene@Co electromagnetic wave absorbing materials.The hollow structure of MXene microspheres constructed with PMMA as a hard template is conducive to optimizing impedance matching and surface modification.In addition,MXene@Co exhibits abundant heterogeneous interfaces,enhancing the interfacial polarization phenomenon during electromagnetic wave absorption.Meanwhile,the surfaceanchored growth of magnetic Co particles forms a magnetic network,which provides a strong magnetic loss capability for the absorber.The hollow structure design significantly enhances the wave absorption performance compared to conventional MXene@Co composites,with a minimum reflection loss of−57.32 dB(effective absorption bandwidth of 5.2 GHz)when the thickness is 2.5 mm(2.2 mm).This work provides a meaningful reference for the design of MXene-based electromagnetic wave absorbing materials.
基金Financial support was provided by the National Science Foundation of China(Grants Nos.51872238 and 21806129)the Fundamental Research Funds for the Central Universities(Nos.3102018zy045 and 3102019AX11)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2020JM-118 and 2017JQ5116)the Fund of the State Key Laboratory of Solidification Processing in NPU(No.11972303)。
文摘A series of silicates with double shell hollow sphere morphology were prepared by hydrothermal method with ultra-high temperature calcined,and used in the field of electromagnetic(EM)wave absorption.By characterizing the chemical composition,crystal structure,micro morphology and EM parameters of the several materials,the evaluation results of EM wave absorption capacity of the materials were obtained.In the discussion section,we will discuss the reasons for the differences in EM wave absorption capabilities of the several silicates from multiple aspects such as EM wave absorption mechanism in detail.Especially for iron-based silicate(HGMs@Fe_(2)SiO_(4))materials,after reasonable composition and morphology design,the minimum reflection loss(RLmin)reached up to-41.14 d B with a matching thickness(d)of 3.4 mm,and the corresponding effective absorption bandwidth(f_(E),RL<-10 d B)was 6.80 GHz.Because of the wide EM wave absorption bandwidth,light weight and low water absorption,this kind of double shell silicate material has gained huge application potential in the EM wave absorption field.
