Poly(3,4‐Ethylenedioxythiophene):Sulfamic Acid Modified Aramid Nanofibers: An Innovative Conductive Polymer With Enhanced Electromagnetic Interference Shielding and Thermoelectric Performance

Abstract The development of alternative conductive polymers for the well‐known poly (3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is of great significance for improving the stability in long‐term using and high‐temperature environments. Herein, an innovative PEDOT:S‐ANF aqueous dispersion is successfully prepared by using sulfamic acid (SA) to modified aramid nanofibers (S‐ANF) as an alternative dispersant for PSS and the subsequent in situ polymerization of PEDOT. Thanks to the excellent film forming ability and surface negative groups of S‐ANF, the PEDOT:S‐ANF films show comparable tensile strength and elongation to unmodified PEDOT:ANF. Meanwhile, PEDOT:S‐ANF has a high conductivity of 27.87 S cm −1 , which is more than 20 times higher than that of PEDOT:PSS. The film exhibits excellent electromagnetic interference (EMI) shielding and thermoelectric performance, with a shielding effectiveness (SE) of 31.14 dB and a power factor (PF) of 0.43 µW m −1 K −2 . As a substitute for PSS, S‐ANF exhibits significant structural and physicochemical properties, resulting in excellent chemical and thermal stability. Even under harsh conditions such as immersing to 0.1 M HCl, 0.1 M NaOH, and 3.5% NaCl solution, or high temperature conditions, the PEDOT:S‐ANF films still maintain exceptional EMI shielding performance. Therefore, this multifunctional conductive polymer exhibits enormous potential and even proves its reliability in extreme situations.