Scalable manufacturing of flexible and highly conductive Ti3C2Tx/PEDOT:PSS thin films for electromagnetic interference shielding

Abstract

The ever-increasing proliferation of miniaturized and wearable electronics demands lightweight and easy-to-process electromagnetic interference (EMI) shielding materials. Herein, we develop flexible micrometer-thick Ti₃C₂T_x/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) nanocomposite films with exceptional electrical conductivity and shielding effectiveness, and with sufficiently uniform thickness. In particular, a ∼7 μm-thick nanocomposite film containing 25 wt% PEDOT:PSS has an exceptional electrical conductivity of 2900 ± 400 S cm⁻¹ and an EMI shielding effectiveness of 55.4 dB after a co-treatment with sulfuric acid and methanol. To the best of our knowledge, this is the highest electrical conductivity ever reported for MXene-based polymer nanocomposites. Besides, the thin film possesses a specific EMI shielding effectiveness of 38 079 dB cm² g⁻¹, which is among the highest values for conductive polymer nanocomposites. The inclusion of PEDOT:PSS endows great film-forming ability to Ti₃C₂T_x suspensions and hampers unwanted phenomena such as the coffee-ring effect. We also implement a wet-transfer approach to form Ti₃C₂T_x/PEDOT:PSS nanocomposite films on complex geometries with curves, angles, and corners, which not only opens up new opportunities for developing EMI shields on complex geometries but also offers a feasible pathway for developing flexible and wearable electronics.