Microwave Attenuation of Graphene Modified Thermoplastic Poly(Butylene adipate-co-terephthalate) Nanocomposites

Thermally tailoring dielectric genes of graphene hybrids for tuning electromagnetic properties

The functions of graphene have garnered significant attention in recent research. A profound understanding of the principles of temperature-dependent electromagnetic responses is crucial for guiding the design of advanced functional materials and devices. From this perspective, the thermally tailored mechanisms of polarization genes and conduction genes are emphasized. The synergistic effect between thermally tailored polarization relaxation and charge transport behaviors is revealed. More importantly, microwave absorption, electromagnetic shielding, and temperature sensing at elevated temperatures are discussed by customizing the conduction and polarization genes. The tunable variable-temperature electromagnetic performance enables the possibilities of diversified electromagnetic energy conversion. Three electromagnetic energy conversion devices for consuming waste electromagnetic energy are predicted, which can support the next generation of energy management and smart devices and promote efficient utilization of resources and sustainable development.

Progress in polymers and polymer composites used as efficient materials for EMI shielding

The explosive progress of electronic devices and communication systems results in the production of undesirable electromagnetic pollution, known as electromagnetic interference. The accumulation of electromagnetic radiation in space results in the malfunction of commercial and military electronic appliances, and it may have a negative impact on human health. Thus, the shielding of undesirable electromagnetic interference has become a serious concern of the modern society, and has been a very perspective field of research and development. This paper provides detailed insight into current trends in the advancement of various polymer-based materials with the effects of electromagnetic interference shielding. First, the theoretical aspects of shielding are outlined. Then, the comprehensive description of the structure, morphology and functionalization of the intrinsic conductive polymers, polymers filled with the different types of inorganic and organic fillers, as well as multifunctional polymer architectures are provided with respect to their conductive, dielectric, magnetic and shielding characteristics.

Exfoliation and Defect Control of Two-Dimensional Few-Layer MXene Ti3C2Tx for Electromagnetic Interference Shielding Coatings

Defect-controlled exfoliation of few-layer transition-metal carbide (f-Ti₃C₂T_x) MXene was demonstrated by optimizing chemical etching conditions, and electromagnetic interference (EMI) shielding coatings were explored. The structural features such as layer morphology, lateral size, layer thickness, defect density, and mechanical stability of the exfoliated f-Ti₃C₂T_x were strongly dependent on exfoliation conditions. By selecting appropriate exfoliation conditions, moderate etching time leads to the formation of quality f-Ti₃C₂T_x with lesser defects, whereas longer etching time can break the layer structure and increase defect density, structural misalignment, and oxidative products of f-Ti₃C₂T_x. The resultant fabricated free-standing flexible f-Ti₃C₂T_x films exhibited electrical conductivity and electromagnetic interference (EMI) shielding effectiveness (SE) in the X-band of about 3669 ± 33 S/m and 31.97 dB, respectively, at a thickness of 6 μm. The large discrepancy in EMI SE performance between quality (31.97 dB) and defected (3.164 dB) f-Ti₃C₂T_x sheets is attributed to interconnections between f-Ti₃C₂T_x nanolaminates interrupted by defects and oxidative products, influencing EMI attenuation ability. Furthermore, the demonstrated solution-processable high-quality f-Ti₃C₂T_x inks are compatible and, when applied for EM barrier coating on various substrates, including paper, cellulose fabric, and PTFE membranes, exhibited significant EMI shielding performance. Moreover, controlling defects in f-Ti₃C₂T_x and assembly of heterogeneous disordered carbon-loaded TiO₂-Ti₃C₂T_x ternary hybrid nanostructures from f-Ti₃C₂T_x by tuning etching conditions could play an enormous role in energy and environmental applications.

3D-MID Technology for Surface Modification of Polymer-Based Composites: A Comprehensive Review

The three-dimensional molded interconnected device (3D-MID) has received considerable attention because of the growing demand for greater functionality and miniaturization of electronic parts. Polymer based composite are the primary choice to be used as substrate. These materials enable flexibility in production from macro to micro-MID products, high fracture toughness when subjected to mechanical loading, and they are lightweight. This survey proposes a detailed review of different types of 3D-MID modules, also presents the requirement criteria for manufacture a polymer substrate and the main surface modification techniques used to enhance the polymer substrate. The findings presented here allow to fundamentally understand the concept of 3D-MID, which can be used to manufacture a novel polymer composite substrate.

Advances in photocatalytic self-cleaning, superhydrophobic and electromagnetic interference shielding textile treatments

The use of nanomaterials in textiles provides many new opportunities and advantages for users and manufacturers; however, it comes with some of its downsides and challenges which need to be understood and overcome for enhancing the applicability of these products. This review article discusses the recent progress in developing self-cleaning and conductive textiles as two of the leading research fields of smart textiles. In particular, different aspects of fabricating nanocoatings for photocatalytic self-cleaning, superhydrophobic and electromagnetic interference (EMI) shielding effect will be brought to light. The theoretical concepts, mechanisms, latest fabrication methods along with their potential applications will be discussed. Moreover, the current drawbacks of these fields will be underlined and some recommendations for future research trajectories in terms of performance, current limitations, sustainability and safety will be proposed. This review article provides a comprehensive review on the state-of-the-art achievements in the field, which will be a valuable reference for researchers and decision makers.

Characterization of Electrical Heating Textile Coated by Graphene Nanoplatelets/PVDF-HFP Composite with Various High Graphene Nanoplatelet Contents

We prepared a horseshoe-pattern type electrical heating textile that was coated with high graphene nanoplatelet (GNP) content (32 wt% to 64 wt%) of graphene nanoplatelet/poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite. Silver-coated conductive yarn is used as electrode in the sample to improve its flexibility and applicability as wearable textile. These graphene nanoplatelet/PVDF-HFP coated samples with various high-contents of graphene were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), sheet resistance analysis, and electrical heating performance analysis. Graphene nanoplatelet/PVDF-HFP coated cotton fabric improved the crystallinity and thermal stability with increasing thw high-content of GNP. With an increasing of the high-content of graphene nanoplatelet in the PVDF-HFP composite solution, the sheet resistance of samples tended to gradually decrease. That of, 64 wt% graphene nanoplatelet/PVDF-HFP composite coated sample (64 GR/cotton) was 44 Ω/sq. The electrical heating performance of graphene nanoplatelet/PVDF-HFP composite coated cotton fabric was improved with increasing the high-content of graphene nanoplatelet. When 5 V was applied to 64 GR/cotton, its surface temperature has been indicated to be about 48 °C and it could be used at a low voltage (<10 V). Thus, a horseshoe-pattern type electrical heating textile that is coated by high content of graphene nanoplatelet/PVDF-HFP composite solution sewn with silver-coated conductive yarn is expected to be applied to glove, shoes, jacket, and so on to improve its wearability and applicability.

Enhancement by Metallic Tube Filling of the Mechanical Properties of Electromagnetic Wave Absorbent Polymethacrylimide Foam

By the addition of a carbon-based electromagnetic absorbing agent during the foaming process, a novel electromagnetic absorbent polymethacrylimide (PMI) foam was obtained. The proposed foam exhibits excellent electromagnetic wave-absorbing properties, with absorptivity exceeding 85% at a large frequency range of 4.9⁻18 GHz. However, its poor mechanical properties would limit its application in load-carrying structures. In the present study, a novel enhancement approach is proposed by inserting metallic tubes into pre-perforated holes of PMI foam blocks. The mechanical properties of the tube-enhanced PMI foams were studied experimentally under compressive loading conditions. The elastic modulus, compressive strength, energy absorption per unit volume, and energy absorption per unit mass were increased by 127.9%, 133.8%, 54.2%, and 46.4%, respectively, by the metallic tube filling, and the density increased only by 5.3%. The failure mechanism of the foams was also explored. We found that the weaker interfaces between the foam and the electromagnetic absorbing agent induced crack initiation and subsequent collapses, which destroyed the structural integrity. The excellent mechanical and electromagnetic absorbing properties make the novel structure much more competitive in electromagnetic wave stealth applications, while acting simultaneously as load-carrying structures.

Smart and Modern Thermoplastic Polymer Materials

Smart and modern thermoplastic polymer materials are defined as novel thermoplastic materials that are capable of responding to external stimuli through a macroscopic output in which the energy of the stimulus is transduced appropriately as a function of external interference. [...].

Electromagnetic Shielding by MXene-Graphene-PVDF Composite with Hydrophobic, Lightweight and Flexible Graphene Coated Fabric

MXene and graphene based thin, flexible and low-density composite were prepared by cost effective spray coating and solvent casting method. The fabricated composite was characterized using Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray (EDX). The prepared composites showed hydrophobic nature with higher contact angle of 126°, -43 mN·m-1 wetting energy, -116 mN·m-1 spreading Coefficient and 30 mN·m-1 lowest work of adhesion. The composites displayed excellent conductivity of 13.68 S·cm-1 with 3.1 Ω·sq-1 lowest sheet resistance. All the composites showed an outstanding thermal stability and constrain highest weight lost until 400 °C. The MXene-graphene foam exhibited excellent EMI shielding of 53.8 dB (99.999%) with reflection of 13.10 dB and absorption of 43.38 dB in 8⁻12.4 GHz. The single coated carbon fabric displayed outstanding absolute shielding effectiveness of 35,369.82 dB·cm²·g-1. The above results lead perspective applications such as aeronautics, radars, air travels, mobile phones, handy electronics and military applications.