# Graphene and Iron Reinforced Polymer Composite Electromagnetic Shielding Applications: A Review
YBa\({}_{2}\)Cu\({}_{3}\)O\({}_{7-x}\) superconductive material was used for EMI shielding, where it was revealed that the composite does not provide effectiveness against electromagnetic  
Figure 1: Studies conducted on EMI shielding. waves [19]. Carbon fibre was also used as EMI shielding, where it was reported that with an increase in the fibre content, the conductivity increases, which enhances the EMI shielding effectiveness [20; 21]. Metals have received attention as EMI shielding materials when used individually and in combination with other materials by forming alloy composites. Moreover, metal fillers were also used for enhancing EMI shielding effectiveness [22; 23; 24; 25; 26]. The most used materials are metal sheets and metal foam. Metal sheets include brass, silver, copper, nickel, tin, and steel. The effectiveness of electromagnetic shielding gets affected by the metal's physical properties such as thickness, weight, permeability, conductivity and solderability, which change the reflection and absorption capabilities. Metals' properties play an important role in the material section as EMI shielding. High conductive metals (brass, copper, silver) reflects electrically dominant waves, whereas, less conductive metal (steel) absorb magnetically dominant waves [27; 28]. Metal foam got hype due to its use in both scientific and industrial applications. Metal foams are composite structures comprised of metal (aluminium) and gas (mainly air is added). The combination of these two results in a disordered wire mesh having low density [29; 30; 31; 32; 33]. Authors earlier gave a brief state of the art review on graphene and iron reinforced polymer composites for electromagnetic shielding applications [28]. However, still there is a gap for an in-dept understanding and comprehensive review. Carbon materials and their composites gained attention in the field of EMI shielding because of their better conductivity and flexibility [34; 35; 36]. Carbon fillers such as carbon black and carbon fibre were also used to achieve EMI shielding effectiveness. Later on, carbon particles and carbon nanotubes were introduced which showed good results [37]. However, a few studies have suggested that carbon-based materials have limited mechanical flexibility, where metal-based materials suffer from corrosion and are heavy in weight, due to which it becomes difficult to achieve high shielding effectiveness [38]. Therefore, there is a great need for developing a shielding material that is light and durable, at low cost, produces no pollution, have comprehensive performance and shielding frequency bandwidth [39]. Thus, the microstructure of the nanomaterials, the structure of the shield and the inclusion of foreign materials such as materials with dielectric or magnetic dipoles play an important role in the absorption of the EM waves [12]. Conducting polymer composites earned recognition in comparison to metal-based composites due to their flexibility, lightweight and resistance to corrosion [40; 41; 42; 43]. Various researchers utilized polymer-based materials as they are lightweight in comparison to metal-based materials. However, polymer-based materials give less shielding against EMI as they are less conductive and have been used in combination with other materials which comes as a good absorber for electromagnetic waves [44; 45; 46; 47; 48]. The polymer-based materials have been identified as the ideal materials for EMI shielding effectiveness [49; 50]. With the introduction of the 5 th Generation (5G) telecommunication system and high frequency range electronic interfaces, the EM pollution has been increased drastically, hence, the coupling effect of EM radiation and signals interferences requires suppressed [51; 52]. Therefore, this study aims to review the past studies conducted to deal with the electromagnetic inferences through graphene, iron and polymer composites.