Mechanically Durable, Highly Conductive, and Anticorrosive Composite Fabrics with Excellent Self-Cleaning Performance for High-Efficiency Electromagnetic Interference Shielding

A Facile Method in Fabricating Flexible Conductive Composites with Large-Size Segregated Structures for Electromagnetic Interference Shielding

To resist the plastic deformation of polymer particles during hot press molding, high molecular weights, and moduli are required for composites with segregated structures, thus the prepared composites exhibit poor flexibility. Also, larger particle sizes can bring lower percolation thresholds while the ensuing greater deformation destroys the conductive network. Moreover, segregated composites still face preparation complexities. Herein, a facile method for developing flexible composites with large-size segregated structures is proposed. First, silver-coated polydopamine-modified reduced graphene oxide (Ag@PrGO), as conductive fillers, is prepared by electroless plating. Next, polydimethylsiloxane (PDMS)-coated polyolefin elastomer (POE) beads are put into a bag containing the fillers. After a simple shaking, the fillers are adhered to the POE surface as the cohesive property of cured PDMS. Finally, flexible composites with large-size segregated structures are obtained via hot pressing. Benefiting from the 2D structure of the Ag@PrGO and the ability to slip, the conductive networks possess adaptable deformability. The prepared composites exhibit excellent electrical conductivity (203.55 S cm-1) at filler volume fractions of 3.4 vol%. The EMI shielding effectiveness can reach 70 dB in the X-band at a thickness of 1.9 mm and remains stable after bending and rubbing damage. This work paves the way for constructing large-size segregated structures.

Yarn-Based Degradable Janus PPDO Fabric for Multifunctional Applications

The growing high standard of people's wear has put forward requirements for fabrics, and multifunctional fabrics have been developed precisely in response to the requirements of the times. However, the incineration of waste fabrics produces a large amount of pollutants, resulting in a massive waste of resources and environmental pollution. Herein, the degradable nanofiber yarns (NYs) with self-cleaning properties were fabricated by in situ growth of SiO2 nanoparticles on the surface of the electrospun poly(p-dioxanone) (PPDO) NYs using the Stöber method. Then, the PPDO NYs were blended with carbon fibers and the PPDO/SiO2 NYs with themselves to form the Janus PPDO fabrics, respectively. The Janus PPDO fabric offered asymmetric wettability and dual personal thermal management properties. The PPDO/C side of the Janus PPDO fabric provided 65.8 °C at 1.5 V or 58.5 °C under one sunlight intensity for radiative heating. The PPDO/SiO2 side exhibited high solar reflectivity (81.8%) and mid-infrared (MIR) emissivity (99.1%), which reduced the skin temperature by 4.6 °C, resulting in radiative cooling. Moreover, the Janus PPDO fabrics display an excellent electromagnetic interference (EMI) shielding performance (53.3 dB). Therefore, yarn-based degradable Janus fabric has a promising future in multifunctional wearable products.

Segregated Conductive Polymer Composite with Fe3O4-Decorated Graphite Nanoparticles for Microwave Shielding

Graphite nanoplatelets (GNPs)-the segregated ultra-high molecular weight polyethylene (UHMWPE)-based composites with hybrid filler-decorated with Fe3O4 were developed. Using X-ray diffraction and scanning electron microscopy, it was shown that the decorated component has the shape of separate granules, or their clusters were distributed evenly over the GNPs surface. The individual Fe3O4 nanoparticles are predominantly rounded, with diameters of approximately 20-60 nm. The use of GNPs/Fe3O4 as a filler leads to significant decreases in the percolation limit φc, 0.97 vol% vs. 0.56 vol% for GNPs/UHMWPE- and (GNPs/Fe3O4)/UHMWPE segregated composite material (SCM), respectively. Modification of the GNP surface with Fe3O4 leads to an essential improvement in the electromagnetic interference shielding due to enhanced microwave absorption in the 26-37 GHz frequency range in its turn by abundant surface functional groups and lattice defects of GNPs/Fe3O4 nanoparticles.

Hydrophobic Composite Foams with Asymmetric Gradient Sandwich Structure for Excellent Electromagnetic Interference Shielding and Photothermal Response

The evolution of contemporary electronics urgently requires the use of versatile electromagnetic interference (EMI) shielding materials in complex environments. Interlayer polydimethylsiloxane (PDMS)/Fe3O4@multiwalled carbon nanotubes (MWCNTs) foams were prepared by a simple physical foaming method with excellent flexibility and electromagnetic wave absorption. The bottom nickel aramid paper (NiP) layer creates a dense conductive network by chemical plating technology, which ensures excellent EMI effectiveness. The upper carbon black (CB)/Fe3O4 layer further improves the absorption performance via conductive loss and magnetic loss. With the effective layout of the impedance matching layer, absorbing layer, and conductive shielding layer, the CB/Fe3O4-PDMS/Fe3O4@MWCNTs-NiP composite material achieves an EMI shielding effectiveness (EMI SE) of 61.7 dB and an absorption coefficient of 0.58 at X-band. In addition, the composite foam provides photothermal conversion and hydrophobicity due to the effective stacking of PDMS and CB/Fe3O4. Thus, the multifunctional composite foam presents a broad range of possible applications, benefiting EMI shielding as well as other specific areas.

Lightweight polyurethane composite foam for electromagnetic interference shielding with high absorption characteristic

Due to the rapid growth of electronic equipment technology, efficient electromagnetic shielding materials are needed for equipment and human protection. Among them, foam shielding materials with absorption as the primary mechanism have higher application value than highly reflective materials. Highly absorbing shielding materials can reduce the secondary pollution caused by electromagnetic wave reflection. In this study, we added Fe3O4@Polyvinyl alcohol (Fe3O4@PVA) and graphene oxide@silver (GO@Ag) into the polyurethane (PU) matrix and constructed Fe3O4@PVA and GO@Ag/PU composite foam by foaming. Fe3O4@PVA and GO@Ag form an excellent network structure in the PU foam skeleton, significantly improving its electromagnetic shielding effectiveness (EMI SE) and mechanical properties. The shielding effectiveness reached 30.9 dB with a specific EMI SE (SSE) of 274.9 dB × cm3 × g-1 at a Fe3O4@PVA filling of 7 wt%, where the electromagnetic wave absorption accounted for more than 80 % of the total EMI SE, proving absorption as the primary shielding mechanism. The results show that Fe3O4, as a ferromagnet, has both the dielectric loss of ferroelectric materials and the hysteresis loss of ferromagnetic materials in electromagnetic shielding, effectively improving the wave absorption performance of composite shielding materials. Therefore, this work provides a promising idea for efficient and lightweight wave-absorbing shielding materials in aerospace, portable electronic devices and lightweight wearable devices.

Hydrophobicity and Improved Corrosion Resistance of Weathering Steel via a Facile Sol-Gel Process with a Natural Rust Film

Weathering steel, which has a protective corrosion product film, is widely used in various construction and landscaping applications. However, it causes metal contamination in the receiving ecosystem via corrosion-induced metal dissolution and rust runoff. Traditional corrosion prevention methods, such as surface coating, also suffer from environmental pollution and high maintenance costs. In this study, we propose a novel method to make the rust film hydrophobic to prevent corrosion while retaining its original appearance. The crystalline rust is used as a natural skeleton, and nano-SiO2 particles are synthesized in situ on it by a facile sol-gel method. The microscopic analysis shows that the flower-like rust flakes provide a primary structure (micrometric scales) and the nano-SiO2 particles form a secondary structure (nanoscale bumps), which is the essential micronanostructure for forming a hydrophobic surface. The as-synthesized film shows strong corrosion resistance, with the corrosion current density being 4 orders of magnitude lower than that of the samples without hydrophobicity. The hydrophobic surface not only prevents corrosive substances from penetrating into the rust layer but also reduces the risk of contamination through its self-cleaning properties. Therefore, the weathering steel with a hydrophobic rust film can be more stable and environmentally friendly for multiscenario applications.

Controlling Nano-to-Microscale Multilevel Architecture in Polymeric Microfibers through Polymerization-Induced Spontaneous Phase Separation

Hierarchically structured polymeric fibers, composed of structural nanoscale motifs that assemble into a microscale fiber are frequently found in natural fibers including cellulose and silk. The creation of synthetic fibers with nano-to-microscale hierarchical structures represents a promising avenue for the development of novel fabrics with distinctive physical, chemical, and mechanical characteristics. In this work, we introduce a novel approach for creating polyamine-based core-sheath microfibers with controlled hierarchical architectures. This approach involves a polymerization-induced spontaneous phase separation and subsequent chemical fixation. Through the use of various polyamines, the phase separation process can be manipulated to produce fibers with diverse porous core architectures, ranging from densely packed nanospheres to segmented "bamboo-stem" morphology. Moreover, the nitrogen-rich surface of the core enables both the chemisorption of heavy metals and the physisorption of proteins and enzymes. Our method offers a new set of tools for the production of polymeric fibers with novel hierarchical morphologies, which has a high potential for a wide range of applications such as filtering, separation, and catalysis.

ZnO nanoparticles coated and stearic acid modified superhydrophobic chitosan film for self-cleaning and oil-water separation

The aim of this study was to prepare superhydrophobic chitosan films using a ZnO nanoparticle coating and stearic acid hydrophobic modification. A 1 % concentration of ZnO nanoparticles and a 1 % concentration of stearic acid generated a superhydrophobic film with the largest contact angle (WCA) of 156°, which was attributed to the synergy of micro/nano-level hierarchical structure and low surface energy modification. The superhydrophobic film showed better stability to acid, alkali, heat, and UV irradiation than a neat chitosan film and a reduction in light transmittance of 14.4 % at 354 nm. The superhydrophobic chitosan film also showed excellent self-cleaning and oil-water separation performance. Our findings will expand the application of chitosan films in food packaging, outdoor self-cleaning materials and oil-water separations.

Sustainable cellulose-based multifunctional material for electromagnetic shielding, flame retardancy and antibacterial

Biomass-based multifunctional electromagnetic shielding materials have attracted extensive interest in academia and industry due to the sustainability of biomass and the environmental adaptability of multifunctional materials. After removing lignin and hemicellulose wood become a porous substrate with aligned cellulose, which is a good platform for building cellulose-based materials. In this work, a cellulose composite with sandwich-like structure was constructed by in-situ polymerization of aniline on delignified wood and coating a PDMS/CNT layer. Benefiting from the natural porous hierarchical structure and the constructed multilayer continuous conductive network, the PDMS/CNT/PANI WA exhibits excellent electrical conductivity (18.6 S/m) and electromagnetic shielding performance (shielding efficiency value of 26 dB at the X band (8.2-12.4 GHz)). The synergistic effect of PANI and CNT endowed the material with excellent flame retardancy (HRR, THR and HRC decreased by 84 %, 53.4 % and 83.3 %) and significant antibacterial activity. Moreover, PDMS imparts a water contact angle of 105° to the material, which acts as a protective layer, further improves the durability of the material. This work provides a new strategy for developing sustainable and multifunctional electromagnetic shielding materials.

Bio-based phytic acid@polyurushiol‑titanium complex coated cotton fabrics with durable flame retardancy for oil-water separation

Bio-based hydrophobic coating modified cotton fabrics with durable flame retardancy are of high interest in the application of oil-water separation for not only avoiding the use of hazardous substances but also improving the fire safety during use. Herein, phytic acid@Polyurushiol‑titanium complex coated cotton fabric was developed using the facile dip-coating method involving the sequential immersion in the solution of poly(ethyleneimine), phytic acid, titanium oxide, and urushiol. The underlying coating accommodated abundance of phytic acid, which imparted excellent flame retardancy to cotton fabric, and the top coating composed of the polyurushiol‑titanium complex endowed cotton fabric with high hydrophobicity that the water contact angle (WCA) was up to 149.8°. The hydrophobicity also guaranteed effective protection of the underlying phytic acid against chemical solvents and abrasion. Besides, the hydrophobic coating allowed cotton fabric for good self-cleaning and effective oil-water separation. Therefore, the preparation of phytic acid@polyurushiol‑titanium complex coated cotton fabric offers a promising approach to construct durable biomass-coated cellulose-based fabric with multifunctionality.

Removal of dyes, oils, alcohols, heavy metals and microplastics from water with superhydrophobic materials

A wide variety of pollutants can be currently found in water that are extremely difficult to remove due to their chemical composition and properties. A lot of effort has been made to tackle this issue that directly affects the environment. In this scenario, superhydrophobic surfaces, which have a water contact angle >150°, have emerged as an innovative technology that could be applied in different ways. Their environmental applications show promise in removing emerging pollutants from water. While the number of publications on superhydrophobic materials has remained largely unchanged since 2019, the number of articles on the environmental applications of superhydrophobic surfaces is still rising, corroborating the interest in this area. Herein, we briefly present the basis of superhydrophobicity and show the different materials that have been used to remove pollutants from water. We have identified five types of emerging pollutants that are efficiently removed by superhydrophobic materials: oils, microplastics, dyes, heavy metals, and ethanol. Finally, the future challenges of these applications are also discussed, considering the state of the art of the environmental applications of superhydrophobic materials.

Recent advances in eco-friendly fabrics with special wettability for oil/water separation

Considering the serious damage to aquatic ecosystems and marine life caused by oil spills and oily wastewater discharge, efficient, environment-friendly and sustainable oil/water separation technology has become an inevitable trend for current development. Herein, fabrics are recognized as eco-friendly materials for water treatment due to their good degradability and low cost. Particularly, fabrics with rough structures and natural hydrophilicity/oleophilicity enable the construction of superwetting surfaces for the selective separation of oil/water mixtures and even complex emulsions. Therefore, superwetting fabrics for efficiently solving oil spills and purifying oily wastewater have received extensive attention. Especially, Janus and smart fabrics are highly anticipated to enable the on-demand and sustainable treatment of oil spills and oily wastewater due to their changeable wettability. Moreover, the fabrication of superwetting fabrics with multifunctional performances for oily wastewater purification can further promote their practical industrial applications, such as photocatalytic, self-cleaning, and self-healing characteristics. However, some potential challenges still exist, which urgently need to be systematically summarized to guide the future development of this research field. In this review, firstly, the fundamental theories of wettability and the separation mechanisms based on special wettability are discussed. Then, superwetting fabrics for efficient oil/water separation are systematically reviewed, such as superhydrophobic/superoleophilic (SHB/SOL), superhydrophilic/superoleophobic (SHL/SOB), SHL/underwater superoleophobic (SHL/UWSOB), and UWSOB/underoil superoleophobic (UWSOB/UOSHB) fabrics. Most importantly, we highlight Janus, smart, and multifunctional fabrics based on their superwetting property. Correspondingly, the advantages and disadvantages of each superwetting fabric are comprehensively analyzed. Besides, super-antiwetting fabrics with superhydrophobic/superoleophobic (SHB/SOB) property are also introduced. Finally, the challenges and future research directions are explained.

Sandwich-Structured Surface Coating of a Silver-Decorated Electrospun Thermoplastic Polyurethane Fibrous Film for Excellent Electromagnetic Interference Shielding with Low Reflectivity and Favorable Durability

Nowadays, high efficiency and low reflection electromagnetic interference (EMI) shielding materials have a wide potential application of electronic fields. However, it is still challenging to achieve long-term durability under external mechanical deformations or other harsh conditions. Herein, sandwich-structured surface coatings with a mixture of polydimethylsiloxane (PDMS)/carboxylated multiwalled carbon nanotube and magnetic ferriferous oxide nanoparticle hybrid fillers (MWCNTs-COOH/Fe₃O₄, MFs) are introduced onto a silver-decorated electrospun thermoplastic polyurethane (TPU) fibrous film to achieve both outstanding low reflective EMI shielding and favorable durability. The surface coatings not only act as an effective absorbing layer but also provide a micro-nano hierarchical superhydrophobic surface. The resultant film shows a remarkable conductivity (361.0 S/cm), an excellent EMI shielding effectiveness (SE) approaching 85.4 dB, and a low reflection coefficient value of 0.61. Interestingly, the obtained film still maintains an excellent EMI SE even after mechanical deformations or being immersed in strong acidic solution, alkaline solution, and organic solvents for 6 h. This work opens a new avenue for the design of low reflective EMI shielding films under harsh environments.

Microskeleton Magnetic Nanofiller Composite with Highly Reliable Superhydrophobic Protection for Long-Lived Electromagnetic Interface Shielding

Superhydrophobic/electromagnetic interference (EMI) shielding materials have received a great deal of attention, attributing to their excellent water repellence characteristic. However, it is really challenging to simultaneously achieve materials with superhydrophobicity, high EMI shielding performance, and long-term stability of these materials that can operate around the clock in harsh service conditions. Herein, a novel strategy to create an integrated microskeleton magnetic nanofiller composite (IMMNC) with exceptional liquid repellency, enhanced EMI shielding effectiveness, and extreme environment reliability is reported. The superhydrophobicity of the IMMNC was maintained after extreme mechanical and chemical damage due to the synergistic enhancement between epoxy-silicone oligomers/polymerized rosin and microskeleton. Consecutively hierarchical micro/nanoarchitectures and conductive pathways endow the IMMNC with a high EMI shielding effectiveness up to 80.7 dB and a satisfactory antifouling capacity for solid and water-based contaminants. More interestingly, this composite still maintains a superior EMI shielding performance after being subjected to ultrasonic vibration, low (-20 °C) or high temperature (300 °C), and even strong acid (1 M), demonstrating its great potential and reliability as a high-performance EMI shielding material resistant to harsh operating conditions. This work provides an efficient and practical solution for developing next-generation EMI shielding materials with high reliability in an all-weather complex and changeable environment.

Structural evolution of MXenes and their composites for electromagnetic interference shielding applications

Nowadays, the extensive utilization of electronic devices and equipment inevitably leads to severe electromagnetic interference (EMI) issues. Therefore, EMI shielding materials have drawn considerable attention, and great effort has been devoted to the exploration of high-efficiency EMI shielding materials. As a novel kind of 2D transition metal carbide material, MXenes have been widely investigated for EMI shielding in the past few years due to their extraordinary electrical conductivity, large specific surface area, light weight, and easy processability. In view of the great achievements in MXene-based materials for EMI shielding, herein, we reviewed the recent studies on the structural design and evolution of MXenes and their composites for EMI shielding. First, the methods for structural control of MXenes, including HF etching, in situ HF etching, fluorine-free etching, electrochemical etching, and molten salt etching, are systematically summarized. Then we illustrate the fundamental relationship between the microstructure of MXenes and the EMI shielding mechanism. In the following, the effects of different synthesis methods and structures of MXene-based composite materials as well as their EMI shielding performances are comprehensively discussed. Lastly, future prospects for the development of MXene-based composite materials in EMI shielding applications are commented on.

Robust Superamphiphobic Fabrics with Excellent Hot Liquid Repellency and Hot Water Vapor Resistance

Superamphiphobic surfaces progress rapidly but suffer from the issues of low repellency to hot liquids, complicated and nonaqueous preparation methods, and low durability. Here, a simple waterborne approach is developed to fabricate robust superamphiphobic fabrics with excellent hot liquid repellency and hot water vapor resistance. First, a perfluorodecyl polysiloxane (FD-POS) aqueous suspension was prepared by hydrolytic cocondensation of (3-glycidyloxy propyl)trimethoxysilane and 1H,1H,2H,2H-perfluorodecyltriethoxysilane with SiO₂ particles. Then, the superamphiphobic fabrics were fabricated by dipping polyester fabrics in the suspension, which were then cured. The fabrics show excellent superamphiphobicity owing to the combination of the hierarchical micro-/nanostructure and FD-POS with very low surface energy. The superamphiphobic fabrics feature excellent hot liquid repellency even for a large volume of 130.0 °C soybean oil and condensed small droplets from ∼90.0 °C water vapor. This is attributed to its high superamphiphobicity, excellent hot water vapor resistance, and outstanding thermal durability. In addition, the superamphiphobic fabrics exhibit high mechanical and chemical durability against washing, abrasion, and immersion in corrosive or organic liquids. Thus, hot liquid repellent superamphiphobic fabrics may find applications in various fields such as antiadhesion of various hot liquids and in efficiently preventing scalding.

Recent Advances in Design Strategies and Multifunctionality of Flexible Electromagnetic Interference Shielding Materials

With rapid development of 5G communication technologies, electromagnetic interference (EMI) shielding for electronic devices has become an urgent demand in recent years, where the development of corresponding EMI shielding materials against detrimental electromagnetic radiation plays an essential role. Meanwhile, the EMI shielding materials with high flexibility and functional integrity are highly demanded for emerging shielding applications. Hitherto, a variety of flexible EMI shielding materials with lightweight and multifunctionalities have been developed. In this review, we not only introduce the recent development of flexible EMI shielding materials, but also elaborate the EMI shielding mechanisms and the index for "green EMI shielding" performance. In addition, the construction strategies for sophisticated multifunctionalities of flexible shielding materials are summarized. Finally, we propose several possible research directions for flexible EMI shielding materials in near future, which could be inspirational to the fast-growing next-generation flexible electronic devices with reliable and multipurpose protections as offered by EMI shielding materials.

Durable Superhydrophobic Coating for Efficient Microplastic Removal

The pollution caused by microplastics around the world is an increasingly significant issue that has to be tackled with different methods and technologies. Here, we report a straightforward and rapid process combining electrodeposition and electrophoresis to produce a durable superhydrophobic coating on an aluminum substrate (UNS A91070) that has a static contact angle (153°), sliding angle (1°), and contact angle hysteresis (1°). Field emission scanning electron microscopy and high-resolution transmission electron microscopy showed the presence of a hierarchical structure with nanolayers that were 70 nm thick. The chemical composition was also analyzed using attenuated total reflectance-Fourier transform infrared spectroscopy and high-resolution X-ray photoelectron spectroscopy, which revealed that the hierarchical structure was composed of zinc laurate (Zn(C11H20COO)2) that decreased the surface free energy of the system. Moreover, the coating showed high durability against abrasion caused by the P1200 SiC paper due to the presence of TiO2 particles in the upper layers as well as the homogeneous chemical composition of the hierarchical structure. Finally, taking advantage of the superoleophilic properties of superhydrophobic surfaces, the ability of the coating to remove high-density polyethylene microplastics from water was studied.

Near-Instantaneously Self-Healing Coating toward Stable and Durable Electromagnetic Interference Shielding

Durable electromagnetic interference (EMI) shielding is highly desired, as electromagnetic pollution is a great concern for electronics' stable performance and human health. Although a superhydrophobic surface can extend the service lifespan of EMI shielding materials, degradation of its protection capability and insufficient self-healing are troublesome issues due to unavoidable physical/chemical damages under long-term application conditions. Here, we report, for the first time, an instantaneously self-healing approach via microwave heating to achieve durable shielding performance. First, a hydrophobic 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS) layer was coated on a polypyrrole (PPy)-modified fabric (PPy@POTS), enabling protection against the invasion of water, salt solution, and corrosive acidic and basic solutions. Moreover, after being damaged, the POTS layer can, for the first time, be instantaneously self-healed via microwave heating for a very short time, i.e., 4 s, benefiting from the intense thermal energy generated by PPy under electromagnetic wave radiation. This self-healing ability is also repeatable even after intentionally severe plasma etching, which highlights the great potential to achieve robust and durable EMI shielding applications. Significantly, this approach can be extended to other EMI shielding materials where heat is a triggering stimulus for healing thin protection layers. We envision that this work could provide insights into fabricating EMI shielding materials with durable performance for portable and wearable devices, as well as for human health care.

Stable super-hydrophobic and comfort PDMS-coated polyester fabric

Super-hydrophobic fabrics have shown great potential during the last decade owing to their novel functions and enormous potential for diver’s applications. Surface textures and low surface energy coatings are the keys to high water repellency. However, the toxicity of nanomaterials, long perfluorinated side-chain polymers, and the fragile of micro/nano-texture lead to the super-hydrophobic surfaces are confined to small-scale uses. Thus, in this article, a stable polydimethylsiloxane (PDMS)-coated super-hydrophobic poly(ethylene terephthalate) (PET) fabric (PDMS-g-PET) is manufactured via dip-plasma crosslinking without changing the wearing comfort. Benefiting from the special wrinkled structure of PDMS film, the coating is durable enough against physical abrasion and repeated washing damage, which is suffered from 100 cycles of washing or 500 abrasion cycles, and the water contact angle is still above 150°. This study promotes the way for the development of environmentally friendly, safe, and cost-efficient for designing durable superhydrophobic coatings for various practical applications.

Towards the Functional Ageing of Electrically Conductive and Sensing Textiles: A Review

Electronic textiles (e-textiles) have become more and more important in daily life and attracted increased attention of the scientific community over the last decade. This interdisciplinary field of interest ranges from material science, over chemistry, physics, electrical engineering, information technology to textile design. Numerous applications can already be found in sports, safety, healthcare, etc. Throughout the life of service, e-textiles undergo several exposures, e.g., mechanical stress, chemical corrosion, etc., that cause aging and functional losses in the materials. The review provides a broad and critical overview on the functional ageing of electronic textiles on different levels from fibres to fabrics. The main objective is to review possible aging mechanisms and elaborate the effect of aging on (electrical) performances of e-textiles. The review also provides an overview on different laboratory methods for the investigation on accelerated functional ageing. Finally, we try to build a model of cumulative fatigue damage theory for modelling the change of e-textile properties in their lifetime.

Asymmetric Superhydrophobic Textiles for Electromagnetic Interference Shielding, Photothermal Conversion, and Solar Water Evaporation

Flexible and multifunctional textiles have potential applications in self-cleaning and portable electronic product applications, but the current problem that needs to be solved is to maintain their inherent breathability and flexibility while expanding other functional applications. Herein, we adopt the layer-by-layer assembly method to develop a multifunctional textile with superior asymmetric superhydrophobicity, excellent electromagnetic interference (EMI) shielding, outstanding photothermal conversion, and solar water evaporation. The synergistic effect of SiO₂ nanoparticles/poly(dimethylsiloxane) (PDMS) and 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) endows the textile with a water contact angle of 160°. MXene provides high conductivity (1200 S/m) and EMI shielding effects (36 dB) for multifunctional textiles. In addition, the multifunctional textile exhibits excellent photothermal conversion, and satisfactory solar water evaporation efficiency (80%) and rate (1.22 kg/(m² h)) under 1 sun. Therefore, the prepared multifunctional textile has great potential in multiscene applications.

Fabrication of elastic, conductive, wear-resistant superhydrophobic composite material

A polydimethylsiloxane (PDMS)/Cu superhydrophobic composite material is fabricated by wet etching, electroless plating, and polymer casting. The surface topography of the material emerges from hierarchical micro/nanoscale structures of etched aluminum, which are rigorously copied by plated copper. The resulting material is superhydrophobic (contact angle > 170°, sliding angle < 7° with 7 µL droplets), electrically conductive, elastic and wear resistant. The mechanical durability of both the superhydrophobicity and the metallic conductivity are the key advantages of this material. The material is robust against mechanical abrasion (1000 cycles): the contact angles were only marginally lowered, the sliding angles remained below 10°, and the material retained its superhydrophobicity. The resistivity varied from 0.7 × 10^–5 Ωm (virgin) to 5 × 10^–5 Ωm (1000 abrasion cycles) and 30 × 10^–5 Ωm (3000 abrasion cycles). The material also underwent 10,000 cycles of stretching and bending, which led to only minor changes in superhydrophobicity and the resistivity remained below 90 × 10^–5 Ωm.

Stretchable Liquid Metal-Based Conductive Textile for Electromagnetic Interference Shielding

Conductive textiles (CTs) are promising electromagnetic interference (EMI) shielding materials. Nevertheless, limited stretchability and poor reliability restrict their potential applications in stretchable electronic devices because of the rigid conductive networks. Herein, a highly stretchable and reliable CT is developed for effective EMI shielding by designing a deformable liquid-metal (LM) coating and polydimethylsiloxane (PDMS) protective layer. The resultant PDMS-LM/Textile exhibits an outstanding EMI shielding efficiency (EMI SE) of 72.6 dB at a thickness of only 0.35 mm while maintaining EMI SEs of 66.0 and 52.4 dB under strains of 30 and 50%, respectively. The corresponding EMI SEs hold 91.7 and 80.3% retention after 5000 stretching-releasing cycles, respectively. The superior and durable EMI SE should be ascribed to the perfect connectivity and good deformability of conductive LM networks. Moreover, the LM coating has a robust fastness to the textile substrate, without any obvious decrease in EMI SE after 10 min of ultrasonic treatment and 100 peeling cycles because of the protective effect of the PDMS layer. This work provides a novel route to developing highly stretchable CTs for advanced EMI shielding applications, especially in the field of highly stretchable electronic devices.

Preparation of Flexible Carbon Fiber Fabrics with Adjustable Surface Wettability for High-Efficiency Electromagnetic Interference Shielding

In the 5G era, for portable electronics to operate at high performance and low power levels, the incorporation of superior electromagnetic interference (EMI) shielding materials within the packages is of critical importance. A desirable wearable EMI shielding material is one that is lightweight, structurally flexible, air-permeable, and able to self-clean. To this end, a bioinspired electroless silver plating strategy and a one-step electrodeposition method are utilized to prepare an EMI shielding fabric (CEF-NF/PDA/Ag/50-30) that possesses these desirable properties. Porous CEF-NF mats with a spatially distributed silver coating create efficient pathways for electron movement and enable a remarkable conductivity of 370 S mm^-1. When tested within a frequency range of 8.2-12.4 GHz, this highly conductive fabric not only achieves an EMI shielding effectiveness (EMI SE of 101.27 dB at 5028 dB cm² g^-1) comparable to a very thin and light metal but also retains the unique properties of fabrics-being light, structurally flexible, and breathable. In addition, it exhibits a high contact angle (CA) of 156.4° with reversible surface wettability. After having been subjected to 1000 cycles of bending, the performance of the fabric only decreases minimally. This strategy potentially provides a novel way to design and manufacture an easily integrated EMI shielding fabric for flexible wearable devices.

Lightweight and Hydrophobic Three-Dimensional Wood-Derived Anisotropic Magnetic Porous Carbon for Highly Efficient Electromagnetic Interference Shielding

Constructing multifunctional characteristics toward advanced electromagnetic interference shielding materials in harsh environments has become a development trend. Herein, the wood-derived magnetic porous carbon composites with a highly ordered anisotropic porous architecture were successfully fabricated through a pyrolysis procedure. The three-dimensional porous skeleton inherited from the wood stock serves as an electrically conductive network and incorporates magnetic Ni nanoparticles homogeneously and firmly embedded within the carbon matrix that can further improve the electromagnetic attenuation capacity. The optimized Ni/porous carbon (PC) composite exhibits an exceptional electromagnetic interference (EMI) shielding effectiveness of 50.8 dB at the whole X band (8.2-12.4 GHz) with a low thickness (2 mm) and an ultralow density (0.288 g/cm³) and simultaneously possesses an extraordinary compressive strength (11.7 MPa) and a hydrophobic water contact angle (152.1°). Our study provides an alternative strategy to utilize green wood-based materials to design multifunctional EMI shielding composites.

Flexible MXene/Silver Nanowire-Based Transparent Conductive Film with Electromagnetic Interference Shielding and Electro-Photo-Thermal Performance

Transparent conductive film (TCF) is promising for optoelectronic instrument applications. However, designing a robust, stable, and flexible TCF that can shield electromagnetic waves and work in harsh conditions remains a challenge. Herein, a multifunctional and flexible TCF with effective electromagnetic interference shielding (EMI) performance and outstanding electro-photo-thermal effect is proposed by orderly coating Ti₃C₂T_x MXene and a silver nanowire (AgNW) hybrid conductive network using a simple and scalable solution-processed method. Typically, the air-plasma-treated polycarbonate (PC) film was sequentially spray-coated with MXene and AgNW to construct a highly conductive network, which was transferred and partly embedded into an ultrathin poly(vinyl alcohol) (PVA) film using spin coating coupled with hot pressing to enhance the interfacial adhesion. The peeled MXene/AgNW-PVA TCF exhibits an optimal optical and electrical performance of sheet resistance 18.3 Ω/sq and transmittance 52.3%. As a consequence, the TCF reveals an effective EMI shielding efficiency of 32 dB in X-band with strong interfacial adhesion and satisfactory flexibility. Moreover, the high electrical conductivity and localized surface plasmon resonance (LSPR) effect of hybrid conductive network endow the TCF with low-voltage-driven Joule heating performance and excellent photothermal effect, respectively, which can ensure the normal functioning under extreme cold condition. In view of the comprehensive performance, this work offers new solutions for next-generation transparent EMI shielding challenges.

Electroless deposition of silver nanoparticles on cellulose nanofibrils for electromagnetic interference shielding films

High-efficient electromagnetic interference (EMI) shielding films were successfully fabricated by electroless deposition of silver nanoparticles (AgNPs) on polydopamine (PDA) functionalized cellulose nanofibrils (CNFs) as building blocks according to a pressured-extrusion film-forming process. PDA was first functionalized on CNFs by oxidative self-polymerization of dopamine (DA) to synthesize CNFs@PDA, on which AgNPs were electrolessly deposited. The obtained CNFs@PDA@AgNPs composite films served as tightly-connected conductive network, so as to significantly improve the whole electrical conductivity of the EMI shielding films. Utilizing CNFs as green and soft matrix, the fabricated CNFs@PDA@AgNPs EMI films show an outstanding mechanical enduring performance. The CNFs@PDA@AgNPs films with weight ratios of CNFs:AgNO₃ = 1:24 exhibited superb electrical conductivity of 1,000,000 S m^-1 and remarkable EMI shielding effectiveness of 93.8 dB at 8.2 GHz in X band. This work provides a simple methodology to achieve surface metallization of insulating fibers to supersede traditional metals for highly efficient EMI shielding applications.

Record-High Transparent Electromagnetic Interference Shielding Achieved by Simultaneous Microwave Fabry-Pérot Interference and Optical Antireflection

As a potential risk to human and environmental health, radio frequency (RF) radiation should be studied due to the higher frequencies and larger bandwidths that may be employed. Electromagnetic interference (EMI) shielding materials can prevent exposure to RF radiation, but most of them are visibly opaque. In this work, we propose and fabricate visibly transparent EMI shielding materials using an ultrathin silver layer sandwiched by oxides (SLSO) as building blocks. The samples with a double-sided SLSO (D-SLSO) structure exhibit the highest EMI shielding effectiveness (SE) of 70 dB at 27.6 GHz (>62 dB on average at 4-40 GHz) and a transmittance close to 90% at a visible wavelength of 550 nm, which is comparable with those of polyethylene terephthalate (PET) and glass substrates. The D-SLSO structure plays a dual role: it suppresses optical reflections as antireflection coatings and enhances EMI shielding via Fabry-Pérot interference. In addition, we discuss the origin of the extraordinary frequency dependence of SE, which monotonically increases, contrary to that of conventional metallic mesh. This report describes SLSO-based transparent EMI shielding materials with record-high SE and visible transmittance that provide optoelectronic applications with robust safety and reliability under RF radiation with high and broad frequencies.

Segregated poly(arylene sulfide sulfone)/graphene nanoplatelet composites for electromagnetic interference shielding prepared by the partial dissolution method

Segregated conductive polymer composites have been proved to be outstanding electromagnetic interference shielding (EMI) materials at low filler loadings. However, due to the poor interfacial adhesion between the pure conductive filler layers and segregated polymer granules, the mechanical properties of the segregated composites are usually poor, which limit their application. Herein, a simple and effective approach, the partial dissolution method, has been proposed to fabricate segregated poly(arylene sulfide sulfone) (PASS)/graphene nanoplatelet (GNP) composites with superior EMI shielding effectiveness (SE) and high tensile strength. Morphology examinations revealed that the GNPs were restricted in the dissolved outer layer by the undissolved cores, and there was a strong interaction between the PASS/GNP layer and the pure PASS core. The resultant PASS/GNP composites showed excellent electrical conductivity (60.3 S m-1) and high EMI SE (41 dB) with only 5 wt% GNPs. More notably, the tensile strength of the PASS/GNPs prepared by partial dissolution reached 36.4 MPa, presenting 136% improvement compared to that of the conventional segregated composites prepared by mechanical mixing. The composites also exhibited high resistance to elevated temperatures and chemicals owing to the use of the special engineering polymer PASS as a matrix.

Flexible and Ultrathin Waterproof Cellular Membranes Based on High-Conjunction Metal-Wrapped Polymer Nanofibers for Electromagnetic Interference Shielding

Ultrathin, lightweight, and flexible electromagnetic interference (EMI) shielding materials are urgently demanded to address EM radiation pollution. Efficient design to utilize the shields' microstructures is crucial yet remains highly challenging for maximum EMI shielding effectiveness (SE) while minimizing material consumption. Herein, novel cellular membranes are designed based on a facile polydopamine-assisted metal (copper or silver) deposition on electrospun polymer nanofibers. The membranes can efficiently exploit the high-conjunction cellular structures of metal and polymer nanofibers, and their interactions for excellent electrical conductivity, mechanical flexibility, and ultrahigh EMI shielding performance. EMI SE reaches more than 53 dB in an ultra-broadband frequency range at a membrane thickness of merely 2.5 µm and a density of 1.6 g cm^-3 , and an SE of 44.7 dB is accomplished at the lowest thickness of 1.2 µm. The normalized specific SE is up to 232 860 dB cm² g^-1 , significantly surpassing that of other shielding materials ever reported. More, integrated functionalities are discovered in the membrane, such as antibacterial, waterproof properties, excellent air permeability, high resistance to mechanical deformations and low-voltage uniform heating performance, offering strong potential for applications in aerospace and portable and wearable smart electronics.

Highly Deformable Porous Electromagnetic Wave Absorber Based on Ethylene-Propylene-Diene Monomer/Multiwall Carbon Nanotube Nanocomposites

The need for electromagnetic interference (EMI) shields has risen over the years as the result of our digitally and highly connected lifestyle. This work reports on the development of one such shield based on vulcanized rubber foams. Nanocomposites of ethylene–propylene–diene monomer (EPDM) rubber and multiwall carbon nanotubes (MWCNTs) were prepared via hot compression molding using a chemical blowing agent as foaming agent. MWCNTs accelerated the cure and led to high shear-thinning behavior, indicative of the formation of a 3D interconnected physical network. Foamed nanocomposites exhibited lower electrical percolation threshold than their solid counterparts. Above percolation, foamed nanocomposites displayed EMI absorption values of 28–45 dB in the frequency range of the X-band. The total EMI shielding efficiency of the foams was insignificantly affected by repeated bending with high recovery behavior. Our results highlight the potential of cross-linked EPDM/MWCNT foams as a lightweight EM wave absorber with high flexibility and deformability.

Durable and Multifunctional Superhydrophobic Coatings with Excellent Joule Heating and Electromagnetic Interference Shielding Performance for Flexible Sensing Electronics

Superhydrophobic coatings have wide applications in many fields. However, superhydrophobic and smart coatings with multifunctionality and their applications in flexible sensing electronics are seldom reported. In this work, durable, superhydrophobic, and anticorrosive coatings with excellent Joule heating and electromagnetic interference (EMI) shielding performance are prepared on the basis of Ag precursor reduction and synchronous nonsolvent induced phase separation. Silver nanoparticles (AgNPs) coated with the copolymer (polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene: SEBS) are uniformly distributed on the target substrate, forming mechanically durable conductive network. SEBS could not only endow the surface coating with superhydrophobicity but also improve the interaction among individual Ag nanoparticles and the interfacial adhesion between AgNPs and the substrate. The multifunctional coating possesses excellent anticorrosive, self-cleaning, and deicing properties. The high conductivity endows the coatings with excellent Joule heating and EMI shielding performance. The multifunctional coating can be applied to a variety of different substrates with outstanding surface stability and reliability. The conductivity for the smart coating can reach as high as 107 S/cm with the EMI shielding effectiveness up to 37.8 dB. At a low applied voltage of 1 V, the conductive fabric can be heated up to over 80 °C in 60 s and displays good recyclability during dozens of heating and cooling cycles. The Joule heating-induced temperature increase could be used for efficient surface deicing. When used for the flexible and wearable strain sensors, the multifunctional coating has a very low strain detection limit of 0.5% and large sensitivity (with the gauge factor as high as 1075) and excellent repeatability. In addition, it can be used for precisely monitoring different body motions, including both large and subtle joint movement.

Ultrathin and Flexible CNTs/MXene/Cellulose Nanofibrils Composite Paper for Electromagnetic Interference Shielding

As the rapid development of portable and wearable devices, different electromagnetic interference (EMI) shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution. However, limited EMI shielding materials are successfully used in practical applications, due to the heavy thickness and absence of sufficient strength or flexibility. Herein, an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration process. The composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9 ± 5.0 MPa and a fracture strain of 4.6 ± 0.2%. Particularly, the paper shows a high electrical conductivity of 2506.6 S m^-1 and EMI shielding effectiveness (EMI SE) of 38.4 dB due to the sandwich structure in improving EMI SE, and the gradient structure on regulating the contributions from reflection and absorption. This strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.