Toughness and High‐Electromagnetic‐Shielding CPM Composite Film with Multilayer Sandwich Structure Based on Mxene

Electromagnetic shielding (EMI) films with excellent EMI and mechanical performances has been a hotspot in the EMI field. Herein, CNF/PDA@MXene (CPM) composite films exhibiting satisfactory mechanical and EMI properties are fabricated via vacuum filtration using PDA@MXene as the shielding layer and CNF/PDA as the mechanical layer. Results revealed that the optimal mass ratio of MXene to hydroxytyramine (DA) is 100:6 and that of CNF to DA is 70:30. The optimal arrangement is comprised by two layers of CNF/PDA and one layer of PDA@MXene. The breaking strength, breaking elongation, and toughness of the CPM composite film are 198.0 MPa, 2.9%, and 3.22 MJ m⁻³, which increased by 27.4, 3.5, and 106 times compared to those of a pure MXene film, respectively. Furthermore, the EMI efficiency of the CPM composite film reached 46.1 dB. Moreover, the EMI performance of the CPM composite film exhibited only slight changes under the conditions of ultrasonic shock, humid environment, and bending for 1000 times.