Fabrics obtained by combining electromagnetic shielding fabrics with different forming methods and structures through multi-layer composite methods are called composite electromagnetic shielding fabrics. Composite electromagnetic shielding fabric has good shielding performance and can absorb and reflect electromagnetic waves at the same time. In addition, it is lightweight, corrosion-resistant, and easy to process. Composite electromagnetic shielding fabrics mainly include conductive polymer electromagnetic shielding fabrics and MXene electromagnetic shielding fabrics.
1. Conductive polymer electromagnetic shielding fabric
Conductive polymer materials can be combined with graphene oxide and metal materials to work together on fabrics to improve the comfort of the fabrics. ZOU and others combined polypyrrole and inorganic graphene oxide using layer-by-layer assembly technology and loaded it on wool fabric. This can not only retain the softness and breathability of wool, but also ensure its electromagnetic shielding performance to meet daily protection needs.
Fabrics that combine conductive polymer materials with metal overcome the problems of easy shedding and oxidation of electromagnetic shielding materials in fabrics made by a single method and poor bonding with the base material, and can improve the electromagnetic shielding effect of the fabric. LIU et al. used PET woven fabrics and nonwoven fabrics as substrates, and used pyrrole in-situ polymerization and electroless nickel (Ni) plating processes to obtain flexible Ni/PPy (polypyrrole)/PET with high conductivity, high bending resistance, and water resistance. Fabric.
2. MXene type electromagnetic shielding fabric
With the advancement of technology, more and more new materials, such as two-dimensional early transition metal carbides/nitrides (MXene), silver nanowires (AgNW) and other new conductive materials, have begun to be widely used. Among them, MXene has good metal conductivity, large specific surface area, good solution processability and relatively low density, so it has broad application prospects. In addition, MXene has very good internal light-to-heat conversion efficiency, high thermal conductivity and strong heat resistance, and has excellent bactericidal properties.
In addition, conductive polymers can be used to improve the interface between MXene and fabric and the structural stability of the fabric. For example, WANG et al. deposited in-situ polymerized PPy-modified MXene sheets onto polyester fabrics, and then applied a silicone coating on them. The SE value of the resulting fabric was around 90dB when it was 1.3mm thick. Ultra-thin silicone The oxyalkane coating allows the fabric to have good hydrophobic properties while maintaining excellent breathability. YIN et al. used solution dipping method and linear polyaniline (PANI) layer-by-layer assembly technology to construct a multi-layer covered PANI/MXene/carbon fiber composite electromagnetic shielding material on the surface of carbon fiber. After 50 times of assembly, the thickness of the material was only 0.36 mm, the electromagnetic shielding efficiency reaches 35.3dB, and has excellent hydrophobicity, self-cleaning performance, breathability, flexibility and cutability.