Development of potassium permanganate (KMnO4) doped Poly methyl methacrylate (PMMA) composite using layered structure for electromagnetic shielding purpose

The authors have studied the electromagnetic interference (EMI) shielding effectiveness (SE) of KMnO4 doped PMMA composites developed by two different methods; one in bulk form of thickness 1.2 mm and another by stacking twelve layers of thin films each of thickness 100 μm. The EMI SE of stacked layered structure of resultant thickness 1.2 mm is achieved about 29 dB in the frequency range 8.0–12.0 GHz. This is remarkably higher than the value of 21 dB achieved for the bulk composite of 1.2 mm thickness. The characteristic EMI-SE graphs obtained using Agilent E82B Vector Network Analyzer in the X band frequency range have been depicted, and the shielding mechanism in these composite have been analyzed. It is found that the SE in this frequency range is dominated by absorption. The study suggests these composites to be a potentially promising material for EMI shielding purpose.