PEDOT:PSS and AgNW synergistically contributed high electromagnetic shielding performance for polyurethane-based composite coating

To meet the electromagnetic shielding requirements of complex shaped products, we prepared an environmentally friendly, efficient electromagnetic shielding coating on polyethylene terephthalate (PET) using water-based polyurethane, silver nanowire (AgNW), and poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS). The addition of PEDOT:PSS not only notably improved the dispersion of AgNWs in the matrix and also acted as bridges between AgNWs, so the coating’s conductivity was greatly enhanced at a low AgNW content. The conductivity and EMI shielding effectiveness (EMI SE) of the coating with only 24.8 μm thickness and 30 wt% AgNWs reached 19,225 S/m and 68.8 dB, respectively. The EMI SE at such a thin thickness and low AgNW content is outstanding compared with previously reported literature. The coating also shows sufficient flexibility and adhesion stability, and mechanical robustness under sonication and chemical environments. Also, the coating can be attached to a variety of representative substrates, such as polypropylene, nylon, PET, glass, wood and metal.