The design and fabrication of efficient microwave absorbing materials with tunable wave attenuation capacity to address the increasing demand for electromagnetic pollution mitigators remains a challenging task.In this...The design and fabrication of efficient microwave absorbing materials with tunable wave attenuation capacity to address the increasing demand for electromagnetic pollution mitigators remains a challenging task.In this study,Ag_(2)Te and a series of Ag/Ag_(2)Te composites have been successfully synthesized by using a facile one-step solvothermal method through varying the molar ratio of the reactants and reaction time.To investigate the microwave absorption performance of these composites,the samples are mixed with polyvinylidene difluoride matrix under different filler ratios.The experimental results indicate that the AT3(where the molar ratio of Ag:Te is 4:1)sample possesses optimal wave dissipation ability with a minimum reflection loss value of−55.98 dB at 15.01 GHz and a maximum effective absorption bandwidth of 4.90 GHz(13.10-18.00 GHz)at a thickness of 1.7 mm when the filler content is 10 wt.%.Moreover,the widest EAB of 6.20 GHz(10.60-16.80 GHz)is recorded in the Ag_(2)Te sample.Meanwhile,it is observed the solvothermal reaction time can effectually influence effective wave absorption frequency.As the reaction time increases,the position of the minimum reflection loss(RLmin)shifts to lower frequencies.The analysis of the wave absorption mechanism demonstrates that the novel crooked one-dimensional linear structure and abundant heterogeneity within the Ag/Ag_(2)Te composite plays an important role in achieving outstanding wave absorption performance.The specific wave absorption mechanism includes conductive loss,multiple scattering,multiple resonant coupling,interface polarization and electric dipole polarization.This work can provide an effective strategy for the design of high-performance MAMs through constituent and morphology modulation.展开更多
In order to alleviate the growing problem of electromagnetic radiation pollution,it is both urgent and challenging to develop electromagnetic wave absorbing materials with strong absorption and wide effective absorpti...In order to alleviate the growing problem of electromagnetic radiation pollution,it is both urgent and challenging to develop electromagnetic wave absorbing materials with strong absorption and wide effective absorption bandwidth(EAB).The structural design of heterojunction surfaces plays an important role in the development of advanced microwave absorbing materials.Building on this concept,three-dimensional nanocomposites Alk-Ti_(3)C_(2)T_(x)/nitro metal phthalocyanine(TNMP)with phthalocyanine derivative NMP-MXene are designed.TNMP composites are prepared by self-assembly of surface hydroxylated treated MXene with floral spherical nitrophthalocyanine.This method effectively constructs rich heterojunction surfaces and induces dipole polarization effect by designing a large number of oxygen vacancies through coordination,which effectively enhances the material attenuation capability while balancing impedance matching characteristics.By modulating the metal centers in the NMP,the coordination mode of the heterojunction surfaces is regulated,and the polarization relaxation loss is improved to achieve excellent electromagnetic wave absorption performance(reflection loss(RL)of-62.12 dB at a thickness of 1.25 mm).And based on the bionic structure design,a unit cycle structure of double-layered butterfly wing skeleton(DLBWS)is constructed to obtain an ultra-wideband electromagnetic wave absorber with an EAB of 12.5 GHz.This research demonstrates a regulatory scheme to elucidate the dipole polarization mechanism and proposes a new method for designing functional materials in ultra-broadband electromagnetic wave absorption.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(No.2024KQ130)the National Natural Science Foundation of China(No.52373259).
文摘The design and fabrication of efficient microwave absorbing materials with tunable wave attenuation capacity to address the increasing demand for electromagnetic pollution mitigators remains a challenging task.In this study,Ag_(2)Te and a series of Ag/Ag_(2)Te composites have been successfully synthesized by using a facile one-step solvothermal method through varying the molar ratio of the reactants and reaction time.To investigate the microwave absorption performance of these composites,the samples are mixed with polyvinylidene difluoride matrix under different filler ratios.The experimental results indicate that the AT3(where the molar ratio of Ag:Te is 4:1)sample possesses optimal wave dissipation ability with a minimum reflection loss value of−55.98 dB at 15.01 GHz and a maximum effective absorption bandwidth of 4.90 GHz(13.10-18.00 GHz)at a thickness of 1.7 mm when the filler content is 10 wt.%.Moreover,the widest EAB of 6.20 GHz(10.60-16.80 GHz)is recorded in the Ag_(2)Te sample.Meanwhile,it is observed the solvothermal reaction time can effectually influence effective wave absorption frequency.As the reaction time increases,the position of the minimum reflection loss(RLmin)shifts to lower frequencies.The analysis of the wave absorption mechanism demonstrates that the novel crooked one-dimensional linear structure and abundant heterogeneity within the Ag/Ag_(2)Te composite plays an important role in achieving outstanding wave absorption performance.The specific wave absorption mechanism includes conductive loss,multiple scattering,multiple resonant coupling,interface polarization and electric dipole polarization.This work can provide an effective strategy for the design of high-performance MAMs through constituent and morphology modulation.
基金supported by the Research Funding of Hangzhou International Innovation Institute of Beihang University(No.2024KQ130)the National Natural Science Foundation of China(No.52373259).
文摘In order to alleviate the growing problem of electromagnetic radiation pollution,it is both urgent and challenging to develop electromagnetic wave absorbing materials with strong absorption and wide effective absorption bandwidth(EAB).The structural design of heterojunction surfaces plays an important role in the development of advanced microwave absorbing materials.Building on this concept,three-dimensional nanocomposites Alk-Ti_(3)C_(2)T_(x)/nitro metal phthalocyanine(TNMP)with phthalocyanine derivative NMP-MXene are designed.TNMP composites are prepared by self-assembly of surface hydroxylated treated MXene with floral spherical nitrophthalocyanine.This method effectively constructs rich heterojunction surfaces and induces dipole polarization effect by designing a large number of oxygen vacancies through coordination,which effectively enhances the material attenuation capability while balancing impedance matching characteristics.By modulating the metal centers in the NMP,the coordination mode of the heterojunction surfaces is regulated,and the polarization relaxation loss is improved to achieve excellent electromagnetic wave absorption performance(reflection loss(RL)of-62.12 dB at a thickness of 1.25 mm).And based on the bionic structure design,a unit cycle structure of double-layered butterfly wing skeleton(DLBWS)is constructed to obtain an ultra-wideband electromagnetic wave absorber with an EAB of 12.5 GHz.This research demonstrates a regulatory scheme to elucidate the dipole polarization mechanism and proposes a new method for designing functional materials in ultra-broadband electromagnetic wave absorption.
