Scalable Fabrication of Nacre‐Structured Graphene/Polytetrafluoroethylene Films for Outstanding EMI Shielding Under Extreme Environment

Abstract

In this work, inspired by the great advantage of the unique “brick‐mortar” layered structure as electromagnetic interference (EMI) shielding materials, a multifunctional flexible graphene nanosheets (GNS)/polytetrafluoroethylene (PTFE) composite film with excellent EMI shielding effects, impressive Joule heating performance, and light‐to‐heat conversion efficiency is fabricated based on the self‐emulsifying process of PTFE. Both PTFE microspheres and nanofibers are employed together for the first time as “sand and cement” to build unique nacre‐structured EMI shielding materials. Such configuration can obviously enhance the adhesion of composites and improve their mechanical property for the application under extreme environment. Moreover, the simple and effective repetitive roll pressing method can be used for the scalable production in industrialization. The GNS/PTFE composite film shows a high EMI shielding effectiveness (SE) of 50.85 dB. Furthermore, it has a high thermal conductivity of 16.54 W (m K)−1, good flexibility, and recyclable properties. The excellent fire‐resistant and hydrophobic properties of GNS/PTFE film also ensure its reliability and safety in practical application. In conclusion, the GNS/PTFE film demonstrates the potential for industrial manufacturing, and outstanding EMI shielding performance with high stability and durability, which has a broad application prospect for electronic devices in practical extreme outdoor environments.

Flexible, Reliable, and Lightweight Multiwalled Carbon Nanotube/Polytetrafluoroethylene Membranes with Dual‐Nanofibrous Structure for Outstanding EMI Shielding and Multifunctional Applications

“…The excellent heat/cold resistance can be ascribed to the regular molecular structure, stable C‐F bonds with a high bond energy, and relatively high molecular weight. [ 40 ]…”

“…[ 39 ] Presently, most of the porous PTFE membranes are fabricated using methods based on stretching‐induced porosity, emulsion spinning, sintering etching processes, and so on. [ 37,40 ] Only a few studies have focused on conductive PTFE composites with a porous structure because it is difficult to simultaneously realize high filler content and high porosity. For example, Huang et al.…”

“…Although the film exhibited outstanding EMI shielding, it was relatively solid without a porous structure. [ 40 ] Despite these encouraging advances, it is still significantly challenging to simultaneously achieve high conductivity, high porosity, fine thickness, and good environmental stability of conductive PTFE membranes.…”

Wearable EMI Shielding Composite Films with Integrated Optimization of Electrical Safety, Biosafety and Thermal Safety

“…In addition, surface‐insulating and flexible CNF@BNNS/AgNW/BC composite films with excellent overall performance, including EMI shielding, antibiofouling, thermal management, and Joule heating have obvious advantages compared to many materials reported in the literature (Figure 7c; Table S6, Supporting Information). [ 12,28,35,47,50,58,70–77 ]…”

“…[ 7–9 ] To effectively combat this problem, a lot of effort has been paid to the development of efficient EMI shielding materials including metal‐type, [ 10 ] carbon‐type, [ 7,11 ] MXene‐type, [ 2,3 ] and conductive polymer composites. [ 6,12,13 ] Many composite materials in different structural forms, such as compact and laminate structures, [ 14–18 ] layer‐by‐layer assemblies, [ 19–21 ] porous foams and aerogels, [ 22–24 ] and segregated structures, [ 25,26 ] have been investigated to enhance the intrinsic EMI shielding property. The latest research indicates that the maximum EMI shielding capability of MXene material can reach 116 dB at a thickness of 40 µm, demonstrating outstanding EMI shielding effectiveness (EMI SE) sufficient to meet the demanding requirements of practical applications.…”