Key Takeaways & Executive Findings
- •• The Janus-type multifunctional ultra-flexible polytetrafluoroethylene-carbon nanotube-Fe3O4/MXene (FCFe/M) membranes were fabricated via a shear-induced in situ fibrillation technique followed by vacuum-assisted filtration. • Thanks to the strategic distribution of the MXene conductive reflection layer and the silk-like FCFe electromagnetic wave’s absorption layer, the membranes achieve robust electromagnetic interference shielding and effective antireflection through the absorption-reflection-reabsorption mechanism. • The membranes exhibit exceptional thermal management performance, including efficient heat dissipation and electrothermal/photothermal conversion capabilities, further enhancing their promising potential for applications in flexible wearable technologies. • The FCFe/M membrane with a thickness of only 84.9 µm delivers outstanding EMI shielding effectiveness of 44.56 dB in the X-band, with a normalized specific SE reaching 10,421.3 dB cm2 g−1, and can reach surface temperatures up to 140.4 °C and 145.7 °C under 3 V voltage and 320 mW cm−2 optical power density, respectively.
Abstract
Herein, a novel Janus-structured multifunctional membrane with integrated electromagnetic interference (EMI) shielding and personalized thermal management is fabricated using shear-induced in situ fibrillation and vacuum-assisted filtration. Interestingly, within the polytetrafluoroethylene (PTFE)-carbon nanotube (CNT)-Fe3O4 layer (FCFe), CNT nanofibers interweave with PTFE fibers to form a stable “silk-like” structure that effectively captures Fe3O4 particles. By incorporating a highly conductive MXene layer, the FCFe/MXene (FCFe/M) membrane exhibits excellent electrical/thermal conductivity, mechanical properties, and flame retardancy. Impressively, benefiting from the rational regulation of component proportions and the design of a Janus structure, the FCFe/M membrane with a thickness of only 84.9 µm delivers outstanding EMI shielding effectiveness of 44.56 dB in the X-band, with a normalized specific SE reaching 10,421.3 dB cm2 g−1, which is attributed to the “absorption-reflection-reabsorption” mechanism. Furthermore, the membrane demonstrates low-voltage-driven Joule heating and fast-response photothermal performance. Under the stimulation of a 3 V voltage and an optical power density of 320 mW cm−2, the surface temperatures of the FCFe/M membranes can reach up to 140.4 and 145.7 °C, respectively. In brief, the FCFe/M membrane with anti-electromagnetic radiation and temperature regulation is an attractive candidate for the next generation of wearable electronics, EMI compatibility, visual heating, thermotherapy, and military and aerospace applications.
1. Introduction
With the rapid advancement of modern electronic devices, electromagnetic interference (EMI) has become a critical concern, necessitating the development of efficient shielding materials. However, conventional EMI shielding materials often suffer from high reflectivity, leading to secondary electromagnetic pollution. Therefore, there is a pressing need for a multifunctional and innovative design that integrates robust shielding and effective antireflection with thin and flexible characteristics.
A rational approach to resolve this paradox is to tailor the local conductivity of materials to fulfill varying requirements, by strategically positioning optimized compositions and architectures in appropriate regions, thereby integrating antireflective and shielding structures within a single asymmetric material. Grounded in impedance matching theory, constructing multilayer materials featuring a continuous conductivity gradient offers the potential for near-perfect antireflective EMI shielding. Despite this approach being conceptually straightforward, the intricate layer-by-layer fabrication process and the weak interlayer interactions substantially compromise the overall material performance. Therefore, developing a simpler and more feasible approach to fabricate asymmetric structures with superior performance remains a significant challenge.
Recently, Janus-structured materials have garnered widespread attention due to their unique asymmetric structure and straightforward fabrication process. In comparison to conventional homogeneous materials, Janus structures possess distinctly different chemical compositions and microstructures on each side, enabling them to exhibit superior multifunctional performance through asymmetric synergistic effects and independent mechanisms. Particularly in the field of EMI shielding, designing one side of the material as an EMW reflective layer composed of high-conductivity materials, and the other side as an EMW absorbing layer based on CPCs can induce an “absorb-reflect-reabsorb” EMI shielding mechanism, which effectively shields EMWs while minimizing reflection effects.
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Runze Shao, Guilong Wang, Jialong Chai, Jun Lin, Guoqun Zhao, Zhihui Zeng, Guizhen Wang (2025). Multifunctional Janus-Structured Polytetrafluoroethylene-Carbon Nanotube-Fe3O4/MXene Membranes for Enhanced EMI Shielding and Thermal Management. Nano-Micro Letters. https://doi.org/10.1007/s40820-025-01647-x
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Frequently Asked Questions
What is the main innovation of this study?
The study presents a novel Janus-structured membrane integrating a conductive MXene layer and a silk-like FCFe absorption layer, achieving enhanced EMI shielding and thermal management in a thin, flexible form.
How does the Janus structure contribute to EMI shielding?
The Janus structure enables an 'absorption-reflection-reabsorption' mechanism, where the MXene layer reflects electromagnetic waves and the FCFe layer absorbs them, reducing reflection and enhancing overall shielding effectiveness.
What are the key performance metrics of the FCFe/M membrane?
The membrane exhibits an EMI shielding effectiveness of 44.56 dB in the X-band with a thickness of only 84.9 µm, and a normalized specific SE of 10,421.3 dB cm2 g−1. It also shows excellent Joule heating and photothermal conversion, reaching temperatures up to 140.4 °C and 145.7 °C under 3 V and 320 mW cm−2, respectively.
What are the potential applications of this membrane?
The membrane is suitable for flexible wearable electronics, EMI compatibility, visual heating, thermotherapy, and military and aerospace applications due to its combined shielding and thermal management capabilities.
How is the FCFe/M membrane fabricated?
The membrane is fabricated via a shear-induced in situ fibrillation technique followed by vacuum-assisted filtration, which allows for the formation of a stable silk-like structure and the strategic distribution of components.
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