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 µm) 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 × 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 °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.