Nanoparticles Synthesized from Lignin Exhibits Improved Electromagnetic Wave Absorbing Properties

Researchers from Nanjing Forestry University in China have successfully synthesized a novel electromagnetic wave (EMW) absorbing adhesive by incorporating lignin, a natural precursor, into a composite material. According to the study, the lignin-based composite exhibits improved EMW absorbing properties, making it a promising candidate for use in plywood preparation. The research, funded by the Natural Science Foundation of Jiangsu Province and the National Natural Science Foundation of China, used a Mannich reaction to coat core Fe3O4 nanoparticles with lignin. The resulting composite demonstrated excellent EMW absorbing properties, with a reflection loss of -29.5 dB at 15.1 GHz, surpassing those of traditional lignin-phenol-formaldehyde (LPF) adhesives.

Key Takeaways:

• The study synthesized a novel EMW absorbing adhesive using lignin as a precursor to prepare Fe3O4@lignin composites.
• The resulting composites exhibited improved EMW absorbing properties, with a reflection loss of -29.5 dB at 15.1 GHz.
• The research utilized a Mannich reaction to coat core Fe3O4 nanoparticles with lignin, enhancing its interfacial polarization and natural resonance properties.
• The study's findings suggested that the lignin-based composite can balance impedance matching and attenuation ability, leading to excellent EMW absorbing performance.
• The research concluded that the use of lignin as a precursor can improve the EMW absorbing properties of LPF adhesives.
• The study has been peer-reviewed and published in the journal Industrial Crops and Products.

Statistics:

• The reflection loss of the Fe3O4@lignin (1:0.5)-phenol-formaldehyde adhesive at 15.1 GHz was -29.5 dB, significantly higher than that of conventional LPF adhesives (-1.95 dB at 16.2 GHz).
• The Fe3O4@lignin (1:0.5)-phenol-formaldehyde adhesive demonstrated the best EMW absorbing properties, surpassing those of Fe3O4 phenol-formaldehyde adhesives (-5.75 dB at 12.1 GHz).
• The complex permittivity and complex permeability measurements revealed that the excellent EMW absorption abilities of the lignin-based composite are owed to the enhancement in interfacial polarization and natural resonance.

Sources:

• VerticalNews, "Nanoparticles Synthesized from Lignin Exhibits Improved Electromagnetic Wave Absorbing Properties", 2020 OCT 20
• Industrial Crops and Products, "Using Lignin As the Precursor To Synthesize Fe3o4@lignin Composite for Preparing Electromagnetic Wave Absorbing Lignin-phenol-formaldehyde Adhesive", 2020
• Elsevier, "Industrial Crops and Products", Radarweg 29, 1043 Nx Amsterdam, Netherlands
• Nanjing Forestry University, Jiangsu Coinnovat Ctr Efficient Proc & Utilizat F, Nanjing 210037, People's Republic of China.