High-performance carbon nanofiber coated cellulose filter paper for electromagnetic interference shielding

A high-performance electromagnetic interference (EMI) shielding material based on carbon nanofiber (CNF) and cellulose filter (CF) paper has been fabricated by a cost-efficient and convenient dip-coating method. The EMI shielding performance of the CF papers with micron level thickness tolerance (2.5-12.7 mu m) have been explored by considering the microstructure, serviceability, electrical conductivity, and number of dip-coating cycles. Field emission scanning electron microscopy of the surface and edge of the composites support the good electrical conductivity, which showed distinct increment in electrical conductivity from 6.6 x 10(-7) to 0.85 S/cm. The number of dip-coating cycles have a significant impact on electrical conductivity, and this has also been studied and inferred after alteration of dipping cycles. The electromagnetic shielding efficiency of CNF-coated CF paper exhibits 24.6 dB with only 25 dip coating cycles. Moreover, from commercially viable points of view, extensive study has been executed to investigate CNF-coated CF papers in the simulated ageing environments viz. water, thermal ageing, and thermo-degradability over a wide range of temperature (ambient to 600 degrees C). All the environmental factors have been simulated on a laboratory scale. The CNF-coated CF papers possess significantly higher mechanical properties than pure CF paper. This type of conductive CNF-coated CF paper is a promising candidate to be used as highly flexible, lightweight, and cost-efficient EMI shielding material in advanced multifunctional application areas.