Flexible Poly(vinylidene fluoride)-MXene/Silver Nanowire Electromagnetic Shielding Films with Joule Heating Performance

Abstract

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.

A Multifunctional Flexible Composite Film with Excellent Multi‐Source Driven Thermal Management, Electromagnetic Interference Shielding, and Fire Safety Performance, Inspired by a “Brick–Mortar” Sandwich Structure

“…The fitting degree of the I – V linear curve reaches 99.7% (Figure 5a), indicating that the current characteristics of PMP‐60 conform to Ohm's law, and it is a reliable electric heater conforms to Joule's law ( Q = U 2 R −1 t ). [ 30 ] Figure 5b,c shows the trend curves of PMP‐60 surface temperature with time under a low voltage of 1–3 V. The PMP‐60 surface temperature produces a low saturation temperature of 20.5 °C at 1 V. However, its saturation temperature reaches 35.6, 51.7, 84.1, and 114.9 °C at 1.5, 2, 2.5, and 3, respectively. Surprisingly, PMP‐60 can undergo sufficient phase transition within 20 s and reaches the thermal comfort temperature of the human body in 50 s with a voltage of just 1.5 V. Apart from that, a plateau appears during the heating and cooling processes, which indicates the PMP‐60 possesses a good thermal storage effect and can continuously provide energy for the human body after fully absorbing heat.…”

MXene in core–shell structures: research progress and future prospects

“…10g-h). Upon checking the high-resolution SEM image, the microstructure of Au anchored on the Ti 3 C 2 T x membrane was revealed, with the characteristic Au (111) recognized when the contact time is over 30 min. A similar redox process on the formation of crystalline Pd on Ti 3 C 2 T x MXene was observed when H 2 PdCl 4 solution was used instead.…”

“…110 Similarly, a sandwich structured film based on poly(vinylidene fluoride)–MXene/silver nanowire is prepared by vacuum filtration followed by a hot compression method. 111 In another example, coaxial electrospinning with a dual-nozzle was deployed to fabricate core–shell MXene/Si@C nanofibers, where Si particles and MXene nanosheets are in the core, wrapped by a robust carbon shell. 112 Fig.…”

Elastomeric Foldable and High-Temperature Endurance Porous Graphene Films with Superior Electromagnetic Interference Shielding Performance

“…Compared to metallic shielding materials, carbon-based conductive EMI-shielding materials are more promising in the next-generation smart and flexible devices in consideration of their lightweight, cost-effective production, chemical inertness, and easy processing . Graphene, carbon nanotubes, carbon nanofibers, and activated carbon and their composite materials have received extensive concern and been rationally designed for EMI shielding. − Among them, graphene-based shielding materials have been highly favored in recent years. Generally, higher electrical conductivity leads to higher shielding performance of graphene materials due to the enlarged impedance mismatch and enhanced conduction loss .…”