# Graphene and Iron Reinforced Polymer Composite Electromagnetic Shielding Applications: A Review
## 6 Discussion  
Exploring the articles, it was revealed that mostly graphene and iron-based composites were utilized within the X-band range. Later, the inclusion of polymers was tested within the same range. However, few studies trace the higher frequency ranges where the role of polymers cannot be disregarded. Figure 8 shows the shielding material composites which were targeted to deal with EMI within the X-band range. A clear understanding can be drawn that the highest shielding effectiveness was achieved by the addition of polymer composites. Whereas the combination of graphene and iron-based composites are not that beneficial to attain the targeted shielding effectiveness. Among polymers, PDMS, PANI, PMMA and PVDF showed remarkable results in the X-band frequency range. However, the role of PMMA needs to be investigated further as it also showed less shielding effectiveness with graphene. Among other polymers, less shielding effectiveness was also seen by PVA, PEI and TPU composites proving that their combinations need further exploration with other suitable materials. In a similar manner, composites were presented in Figure 9 which were utilized to observe the shielding effectiveness in frequency ranges greater than X-band. The higher shielding effectiveness was achieved with PDMS, Epoxy, PVDF and PANI. However, polystyrene (PS) polymer showed poor results in higher frequency. Interestingly, it was revealed that the combination of two polymers, i.e., PVC and PANI gave good shielding effectiveness, however, the inclusion of two polymers to form one single composite needs further investigation. In a few studies, researchers calculated the reflection loss only instead of providing total shielding effectiveness where the summary is provided in Figure 10. A higher reflection loss was observed in epoxy, PEDOT, TPU and PANI polymer composites. Interestingly, graphene and iron-based composites also showed a remarkable reflection loss. However, in a few studies, the inclusion of polymer composites showed less reflection loss. Figure 8: Composites shielding effectiveness within X-band range. Initially, metals were used as electromagnetic shielding materials to deal with electromagnetic inferences, however, studies showed that due to rigidness, ductile nature, heavyweight, and corrosion effect, they were not endorsed for additional utilization. Later, graphene emerged as a promising new material in the field of EMI where it showed remarkable results. Though individually it possesses less dielectric or magnetic properties yet, with the combination of iron and polymer composites, it showed excellent shielding effectiveness. Polymers, less explored, but effective, also showed significant results with a combination of graphene, where shielding effectiveness was achieved in a higher frequency range. However, there is a need for further exploration of graphene, iron-based polymer composites at higher frequencies as most of the researchers worked on X-band frequency  
Figure 10: Reflection Loss. Figure 9: Composites shielding effectiveness higher than X-band range. range or slightly touch Ku-band. The graphene and iron base conductive polymer composites (CPC) provides maximum shielding effectiveness for a very short duration and decreases drastically with the increase in the X-band frequency range which is a problem and is very less explored with this family. The role of increasing thickness and loading cannot be ignored as in most of the studies, the shielding effectiveness was increased by increasing the filler content and thickness. However, there is a need to explore the new combinations to provide better shielding effectiveness in the higher frequency range. Moreover, it was observed that the combination of two polymers came up with better shielding performance yet requires further study. Those polymers which performed excellently in a higher frequency range can be combined by making an adequate synthesis.