Multifunctional syndiotacticity-rich poly (vinyl alcohol)/MXene sediment for multilayered composite films with effective electromagnetic interference shielding and thermal conductivity

Utilizing remarkable polymer matrix and efficient filler to propose an ingenious strategy for designing composite films synergistically with high electromagnetic interference shielding effectiveness (EMI SE) and thermal conductivity. Herein, a novel type of flexible composite film based on syndiotacticity-rich poly (vinyl alcohol) (sPVA)/modified MXene sediment (mMS) is fabricated through an alternating casting approach. The sPVA/mMS multilayered film containing effective noncovalent combining between sPVA layer and mMS layer not only presents a high strength of ∼66.3 MPa but also possesses a superior electrical conductivity of 683 S/m. Notably, the mMS layer with dense conductive and thermal networks endows the 95-μm-thick composite film with the synergy of favorable EMI SE (∼15.8 dB) in the X band and impressive in-plane thermal conductivity (3.31 W/mK, enhanced by ∼2365%). Moreover, this multilayered architecture realizes multiple internal reflection-absorption of microwaves and efficient heat dissipation, while confers the film with advantageable flame retardancy and significant water resistance. Therefore, sPVA-based composite films from MS provide a promising solution for the development of multifunctional polymeric materials tailored for upcoming electronic devices in challenging environments.