Stretchable Water‐Repellent PEDOT:PSS‐Impregnated Polyurethane Nanofiber Mats for Electromagnetic Interference Shielding

High-performance wearable textiles made from poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) hold great promise for electromagnetic interference (EMI) shielding in military and healthcare systems. However, achieving an optimal balance of resilience, flexibility, and electrical properties is challenging due to weak interfacial interactions between PEDOT:PSS and the host substrates. In this study, a robust and stretchable wearable textile fabricated via vacuum-assisted impregnation of PEDOT:PSS is presented onto an electrospun polyurethane (PU) nanofiber mat. The process creates a convoluted interlock network at the interface layer between PEDOT:PSS and PU nanofiber mat, enhanced by the large contact area, effective chemical interactions, and vacuum-induced pressure. This results in exceptional tensile strength of 51.2 MPa, 207% elongation, and 86% elastic recovery, surpassing the practical requirement threshold of wearable textiles and fibers. The robust PU-PEDOT:PSS nanofiber mat shows a normalized EMI shielding effectiveness value of 365.2 dB mm^-1 at an ultrathin thickness of 100 µm. This textile is capable of maintaining its shielding performance after continuous loading and unloading cyclic tests up to 100% strain. Additionally, a one-step, durable, fluorine-free spray coating is introduced to protect the textile from moisture and dust, thereby extending its service life for practical outdoor applications.