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Anisotropic cellulose nanofibril composite sponges for electromagnetic interference shielding with low reflection
Yiming Chen1, Heng Luo2, Hongtao Guo3
1Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; Key Laboratory of Urban Rail Transit Intelligent Operation and Maintenance Technology & Equipment of Zhejiang Province, College of Engineering, Zhejiang Normal University, Jinhua 321004, China.
A novel anisotropic composite sponge made of cellulose nanofibrils and silver nanowire@Fe3O4 nanoparticles effectively shields electromagnetic interference (EMI). This advanced material offers low density and excellent conductivity for reducing electromagnetic pollution.
Area of Science:
- Materials Science
- Nanotechnology
- Electromagnetics
Background:
- The rapid growth of the electronics industry has led to significant electromagnetic pollution, necessitating effective shielding solutions.
- Electromagnetic interference (EMI) poses a growing challenge, impacting device performance and potentially human health.
- Developing lightweight, efficient EMI shielding materials is crucial for modern electronic applications.
Purpose of the Study:
- To prepare an anisotropic composite sponge for electromagnetic interference shielding.
- To investigate the synergistic effects of cellulose nanofibrils (CNFs), silver nanowires (AgNWs), and Fe3O4 nanoparticles.
- To optimize the composite structure for enhanced EMI shielding performance and reduced secondary reflection.
Main Methods:
- Fabrication of an anisotropic composite sponge using CNFs and chemically co-precipitated AgNW@Fe3O4.
- Characterization of the composite sponge's physical and electromagnetic properties, including density, magnetization, and conductivity.
- Tuning the AgNW to Fe3O4 ratio and loading to minimize reflection loss and improve impedance matching.
Main Results:
- The composite sponge demonstrated low density (16.76 mg/cm³), good saturation magnetization (4.21 emu/g), and electrical conductivity (0.02 S/cm).
- Anisotropic EMI shielding properties were achieved due to the material's structure and composition.
- Optimized AgNW@Fe3O4 loading (0.15 vol%) resulted in low reflection loss (2.3 dB, 7.2% of total loss) by improving interface impedance mismatch.
Conclusions:
- The developed anisotropic composite sponge is a promising material for electromagnetic interference shielding.
- The synergistic effects between CNFs, AgNWs, and Fe3O4 contribute to the material's excellent performance.
- This material shows potential for alleviating secondary reflection electromagnetic pollution in electronic devices.
