Modulation of multifunctional electric dipoles on MXenes for boosting electromagnetic interference shielding

Free-standing MXene films are recognized as excellent electromagnetic interference (EMI) shielding walls owing to their high conductivity, laminate structures, and abundant terminations. Here, we report conjugated polymers of PBTz-SO3Na, PBTz-SO3TBA, and PEDOT:PSS, respectively, electrostatically assembled on interlayer surfaces of Ti3C2Tx MXene generating tunable electric dipoles, accompanied by improvements of conductivity, oxidation resistance, and mechanical stability, to ultimately enhance EMI shielding performance. PEDOT2+ (or TBA+) cations on Ti3C2Tx surfaces induce reversely strong polarized dipoles and enhance conductivity for more electromagnetic wave (EW) attenuation. By increasing the anchored polymers, the enhanced absorption attenuation ensures complete attenuation of incident EW, revealing a dual mechanism of reflection and absorption for EW shielding. At last, the Ti3C2Tx anchored with PEDOT2+ (or TBA+) achieves EMI shielding effectiveness approaching 100 dB at 20-μm thickness. Briefly, multifunctional engineering in electric dipoles between MXene interlayers opens an unexplored avenue for designing efficient EMI shielding materials.