Polymeric films with high electromagnetic
interference (EMI) shielding
effectiveness (SE) and polyfunctionality are highly desirable for
wearable electronic devices. Herein, a sandwich-structured EMI shielding
film with Joule heating performance composed of a poly(vinylidene
fluoride) (PVDF) layer and a conductive filler layer (silver nanowire
(AgNW) and MXene) was constructed by electrostatic spinning, vacuum-assisted
filtration (VAF), and hot compression. An independent AgNW layer endowed
the film with predominant EMI shielding performance at a low conductive
filler content. A high EMI SE of 45.4 dB was obtained in the X band
at a AgNW fraction of 1.28 wt %. The introduction of MXene improved
the connection of the AgNW networks, thereby further enhancing the
electrical conductivity and imparting the film with long-term stability.
The as-obtained PVDF-AgNW/MXene film exhibited an outstanding EMI
SE of 47.8 dB and only a slight decrease in EMI SE was detected after
2000 bending cycles. Besides, the PVDF-AgNW/MXene film exhibits excellent
Joule heating performance. The surface temperature of the film could
exceed 77 °C under an applied voltage of 2.5 V. Therefore, our
sandwich-structured film with enhanced EMI shielding and Joule heating
performance can be used for flexible electronic device applications
in extreme conditions.