Direct coating of copper nanoparticles on flexible substrates from copper precursors using underwater plasma and their EMI performance

Abstract The metal coated textiles and polymer films have become increasingly important in view of electromagnetic interference (EMI) shielding. In this study, we propose a simple underwater plasma system for direct coating of copper nanoparticles on textiles and polymer films to intercept electromagnetic wave. The proposed system can synthesize copper nanoparticles and coat it on substrate at once. We analyzed the characteristics of coating layer in order to optimize coating fabrication. When the copper nanoparticles were coated using optimized condition, the thickness of coating layer is about 1 μm and sheet resistance is about 95.44 mΩ/sq. The improved conductivity of polyimide film and nonwoven fabric significantly contributed to effective shielding of electromagnetic interference measured at 38.83 and 82.31 dB in frequency from 1 to 10 GHz.