In-situ reduction of silver by surface DBD plasma: a novel method for preparing highly effective electromagnetic interference shielding Ag/PET

Electromagnetic interference (EMI) shielding composites with good flexibility and weatherability properties have attracted increased attention. In this study, we combined the surface modification method of sub-atmospheric pressure glow discharge plasma with in situ atmospheric pressure surface dielectric barrier discharge plasma (APSDBD) reduction to prepare polyethylene terephthalate supported silver (Ag/PET). Due to the prominent surface modification of PET film, mild plasma reduction, and effective control of the silver morphology by polyvinylpyrrolidone (PVP), a 3.32 mu m thick silver film with ultralow sliver loading (0.022 wt%) exhibited an EMI shielding efficiency (SE) of 39.45 dB at 0.01 GHz and 31.56 dB at 1.0 GHz (>30 dB in the range of 0.01-1.0 GHz). The SEM results and EMI shielding analysis indicated that the high performance originated from the synergistic effect of the formation of silver nanoparticles (AgNPs) with preferentially oriented cell-like surface morphologies and layer-by-layer-like superimposed microstructures inside, which demonstrated strong microwave reflection properties. Fourier transform infrared spectrometer and x-ray diffractometer showed that the surface structures of the heat-sensitive substrate materials were not destroyed by plasma. Additionally, APSDBD technology for preparing Ag/PET had no special requirements on the thickness, dielectric constant, and conductivity of the substrate, which provides an effective strategy for manufacturing metal or alloy films on surfaces of heat-sensitive materials at a relatively low cost.

Automated summary

In this study, a novel polyethylene terephthalate supported silver (Ag/PET) composite with high flexibility and weatherability properties was prepared by combining sub-atmospheric pressure glow discharge plasma surface modification method with in situ atmospheric pressure surface dielectric barrier discharge plasma (APSDBD) reduction. The Ag/PET composite exhibited excellent EMI shielding efficiency due to the formation of silver nanoparticles with preferentially oriented cell-like surface morphologies and layer-by-layer-like superimposed microstructures, demonstrating strong microwave reflection properties. Additionally, the APSDBD technology used for preparing Ag/PET did not require specific substrate thickness, dielectric constant, or conductivity, providing an effective and cost-efficient strategy for manufacturing metal or alloy films on surfaces of heat-sensitive materials.